Moving beyond Weight: A Narrative Review of the Dietary and Lifestyle Management for Reducing Cardiometabolic Risk in Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder experienced by women. PCOS is a lifelong condition associated with reproductive, metabolic, and psychological presentations. PCOS is also linked with increased prevalence of cardiometabolic risk factors. While an association between body weight and PCOS has been noted, cardiometabolic risk factors are prevalent in individuals with PCOS across body weights. Currently, no consensus exists as to the most appropriate lifestyle strategy for mitigating cardiometabolic risk in PCOS. A large proportion of the literature is focused on weight loss for individuals with PCOS who are overweight or experience obesity, despite PCOS being prevalent across body sizes. The aim of this narrative review is to assess dietary and lifestyle interventions aimed at reducing cardiometabolic risk in individuals with PCOS across body sizes. A total of 51 articles are included in this review. Overall, randomized controlled trials are limited and most studies focus on weight loss, excluding individuals classified within a healthy body weight range. Studies that modified the dietary pattern without an energy deficit saw improvements in cardiometabolic risk. Thus, less restrictive dietary approaches may be effective at reducing cardiometabolic risk in this population. This review also highlights the need for more sustainable lifestyle interventions that meet the needs of individuals with PCOS of varying body weights.


Introduction
Polycystic ovary syndrome (PCOS) is the most common endocrine disorder experienced by women, affecting up to 20% of reproductive age women worldwide [1,2].PCOS is characterized and diagnosed by the presence of menstrual irregularities, hyperandrogenism, and polycystic ovaries [2].The symptoms experienced by individuals with PCOS vary but can include infertility; hirsutism, or excessive hair growth in areas males tend to have hair; thinning hair; weight gain or difficulty losing weight; acne or oily skin; and acanthosis nigricans, a thickening of dark patches on the skin [2].PCOS is a lifelong condition associated with reproductive, metabolic, and psychological presentations [1,3,4].
Having a higher BMI appears to exacerbate insulin resistance by approximately 15% in individuals with PCOS [32].Yet the correlation between BMI and insulin resistance has also been observed in controls without PCOS [10,29], suggesting that BMI is likely not the sole contributor to the higher prevalence of cardiometabolic risk factors observed in individuals with PCOS.Furthermore, observational studies that included BMI-matched controls still identified a higher prevalence of cardiometabolic risk factors in individuals with PCOS, irrespective of BMI [10,21,[28][29][30][31]. Additionally, observational studies that have included individuals with PCOS with a healthy BMI (18.5-24.9kg/m 2 ) still identified a higher prevalence of cardiometabolic risk factors between individuals with and without PCOS [10,11,[21][22][23]25,28,30,31,33].This suggests that weight and BMI alone likely do not explain the prevalence of cardiometabolic risk factors observed in the PCOS population.The level of central adiposity likely plays a key role in cardiometabolic risk, as insulin resistance has been associated with higher levels of central adiposity in the PCOS population [32,[34][35][36].
As the research literature demonstrates that dietary intake is a modifiable risk factor for cardiometabolic risk [37,38], the dietary intakes of individuals with and without PCOS have been explored.Despite individuals with PCOS having a higher prevalence of cardiometabolic risk factors, a systematic review and meta-analysis of 39,471 women with PCOS found that individuals with PCOS overall had comparable total energy, carbohydrate, fat, and protein intakes than individuals without PCOS [39].Thus, energy intake alone may not be able to explain the higher prevalence of cardiometabolic risk in individuals with PCOS.
Yet observational studies suggest that the dietary intakes for individuals with PCOS may be associated with disease severity [14,21,40], including inflammatory status [21], insulin resistance [21,40], hirsutism [40], and cardiovascular health [14].Lower intakes of key nutrients associated with health, such as complex carbohydrates [21], fiber [11,21,23,25,28], unsaturated fatty acids [21], omega-3 polyunsaturated fatty acids [15,21], vitamin A, folate, vitamin C [11], vitamin D, and magnesium [39], have been reported for individuals with PCOS compared to individuals without.Moreover, higher intakes of nutrients associated with poorer health outcomes, such as simple carbohydrates [21] and saturated fatty acids, have been reported for individuals with PCOS [21].Furthermore, individuals with PCOS have been found to have a larger intake of foods high in salt, sugar, fat, and energy, with little to no protein, vitamins or minerals [25].Furthermore, a higher adherence to an anti-inflammatory dietary pattern has been linked to lower PCOS risk [11,39,41].Overall, women with PCOS have either poorer or comparable intakes of major food groups, including grains, fruits, vegetables, proteins, seeds, nuts, and dairy [39], as well as micronutrients, calcium, zinc, iron, folic acid, and vitamin D [39], suggesting room for improvement in the overall dietary patterns of individuals with PCOS.
While a healthy lifestyle is vital for the management of PCOS, currently, no consensus exists as to the most appropriate lifestyle strategy for managing PCOS.A large proportion of the literature is focused on weight loss for individuals with PCOS [42][43][44][45], despite PCOS being prevalent across body sizes [18,46].Similarly, the literature tends to only include overweight or obese individuals as study participants [18,39,43,47].Yet the overall relationship with PCOS and obesity is quite complex [4].With a large proportion of research being conducted in medical centers [4,18,39], individuals at higher body weights may present with worse clinical presentations and perhaps are more likely to be diagnosed [18], referred to other providers [4,48,49], and ultimately included in the research.When comparing the prevalence of obesity in individuals with PCOS in medically unbiased or unreferred populations, the BMI distribution between individuals with and without PCOS appears to be more similar [4,48,49].Thus, the overall understanding of PCOS management among individuals with different BMIs is greatly limited.
Additionally, individuals with PCOS have higher psychological concerns, including body image distress and disordered eating [1,[50][51][52][53][54], making weight-focused interventions potentially inappropriate.Furthermore, weight loss interventions may not be sustainable and potentially lead to greater risk in the long term [55][56][57][58][59]. Lastly, there are benefits to a healthy lifestyle even in the absence of weight loss [1].Thus, understanding lifestyle approaches that improve cardiometabolic risk but perhaps are not solely focused on weight loss are needed for this population to understand future directions for the nutritional management of PCOS.The 2023 International Evidence-Based Guidelines for the Assessment and Management of PCOS recommends that healthy lifestyle behaviors should be recommended to all women with PCOS and should be tailored to allow for a flexible, individual approach that avoids unduly restrictive or nutritionally unbalanced diets [1].Thus, the aim of this narrative review is to assess the dietary and lifestyle interventions aimed at reducing cardiometabolic risk in individuals with PCOS across body sizes.

Methods
A literature search was conducted between June 2021 and April 2023 using PubMed and CINAHL to identify intervention studies that examined the relationship between lifestyle and cardiometabolic risk factors in individuals with PCOS.PubMed MeSH search terms with Boolean functions included "polycystic ovary syndrome" AND "diet" OR "exercise" AND "heart disease risk factors" OR "glucose metabolism disorders."The search was limited to original human subjects research published in English between 1989 and 2023.Intervention studies were included if they targeted adult individuals with PCOS across weight and BMI ranges.Furthermore, selected studies must have included at least one anthropometric measure (body weight, BMI, WC, or body composition), as well as one biochemical (lipid profile and insulin or glucose concentrations) or clinical (blood pressure) marker in their outcomes.By including studies that measured at least one biochemical or clinical marker in addition to one anthropometric measure, we identified studies that looked at measures of cardiometabolic risk other than solely body weight, as our purpose was to review the literature on lifestyle interventions to mitigate cardiometabolic risk for individuals with PCOS across body sizes.
Studies were excluded if they were not published in English, examined adolescents, or did not contain at least one anthropometric measure as well as either a biochemical or clinical marker.Additionally, studies were excluded if the primary intervention included a vitamin, mineral, herbal supplement, or medication.Studies were categorized and organized into solely dietary interventions or lifestyle interventions.Dietary interventions were defined as interventions that modified different components of the diet, including energy intake, macronutrient composition, dietary pattern, or eating behavior, whereas lifestyle interventions modified the diet (as defined above) and included an additional behavioral modification (e.g., exercise or cognition).Dietary intervention studies were organized by the component of the diet altered.Lifestyle intervention studies were organized by the type of dietary and lifestyle behavior that was modified.

Results
A total of 51 studies (37 dietary intervention, 14 lifestyle intervention) were included in this review.The dietary strategies utilized varied widely, spanning from dietary changes in the form of energy restrictions to modifications of the dietary patterns without energy restriction.The additional behavioral modifications of the lifestyle varied widely and included structured and unstructured exercise, as well as cognitive behavior therapy interventions.There were a variety of diagnostic criteria used to diagnosis PCOS across studies, including Rotterdam, the 1990 National Institute of Health, and Androgen Excess Society criteria.A large majority of the studies diagnosed PCOS utilizing the Rotterdam criteria (55%).The studies included in the review are discussed below.

Dietary Interventions
As summarized in Table 1, the studies have examined the impact of dietary interventions on cardiometabolic risk factors in individuals with PCOS.These dietary interventions include changes in energy restriction, macronutrient distribution, dietary pattern, eating behavior, energy restriction and macronutrient distribution, and energy restriction and dietary pattern.
Insulin sensitivity, glucose, and lipid profile.
No control group, small sample size, and short duration.
Short-term studies have shown that after following a VLCD, individuals with PCOS had lower body weight [60][61][62], and improved glucose [62] and insulin measures [60][61][62].Longer term studies, consisting of a VLCD followed by a low-calorie diet for a period of six to seven months, have also observed decreases in body weight and insulin measures in participants with PCOS [63][64][65].Yet the initial changes from following the VLCD may not be sustainable.Despite participants still following a low-calorie diet, the weight loss and decreases in total cholesterol and triglyceride concentrations from baseline were no longer significant six to seven months later [64,65].Thus, the improvements in cardiometabolic risk factors from a VLCD may not be sustainable, despite continuing to follow a low-calorie diet.
Other Energy-Restricted Diets.Energy-restricted diets, ranging from 500-1000 kcal/day energy deficits, have also been studied for individuals with PCOS with overweight and obesity (Table 1).Studies that explored energy restriction included replacing two meals daily with a meal replacement beverage [68], a 12-week 1000 kcal/day caloric deficit [70], and a 12-week 500 kcal/day deficit [71].At the end of the meal replacement beverage intervention, significantly more PCOS participants exhibited insulin resistance post-intervention [68], implying weight loss itself may not always improve insulin resistance.While the researchers stated that reductions in insulin resistance might rely on reduction in a certain level of abdominal fat, there were no significant differences in total fat mass nor total fat-free mass markers between PCOS and non-PCOS participants in the study [68].
With a 1000 kcal/day deficit intervention, researchers found significant decreases in weight, WC, and fasting insulin [70].Yet other researchers found that a 500 kcal/d deficit was also sufficient for an average weight loss of 3.5% that was significantly associated with a reduction in fasting blood glucose, plasma insulin, and LDL-C concentrations, as well as HOMA-IR [71].Thus, a smaller, and perhaps more realistic, energy deficit has cardiometabolic benefits comparable with larger energy deficits.
Overall, these studies indicate that an energy-restricted diet may be beneficial at improving cardiometabolic risk factors in individuals with PCOS with overweight and obesity.Yet these studies are limited in their generalizability due to the lack of a detailed description of the intervention [67], racial and ethnic diversity of participants [68], discussion of the demographic characteristics [70], and control groups [70,71], as well as short study duration.The cardiometabolic risk factors measured differ across studies, further challenging a comparison of results.Furthermore, these energy-restrictive diets are likely not appropriate for individuals with PCOS within a healthy BMI range.

Macronutrient Distribution
Low-Carbohydrate (CHO) Diet.Other studies (Table 1) have looked to moderate or reduce the number of carbohydrates consumed to help mitigate cardiometabolic risk factors in individuals with PCOS across BMI ranges.The definition of low CHO varies across the studies included in this review, ranging from 40-43% of energy coming from CHO.These percentages of energy from CHO are not much lower than the Dietary Reference Intakes Acceptable Macronutrient Distribution Range (AMDR) for CHO, 45-65%, perhaps making these interventions more aptly described as moderate CHO rather than low CHO.All of the studies were designed to be eucaloric and found a low-CHO diet to lower fasting insulin [72][73][74], glucose [73], total cholesterol [72,73], LDL-C concentrations [73,74], HOMA-IR [73], and area under the curve insulin [74], as well as to improve insulin sensitivity [73] in individuals with PCOS.
The strengths of these studies include the provision of food for the study participants [72][73][74], randomization and blinding [73], and diverse samples [73].Yet the limitations included small sample sizes [72,74] and short intervention periods [72,74].Furthermore, researchers in one study purposively selected participants with overweight and obesity, stating that the findings would be more applicable to the general population [72].Yet PCOS does affect individuals with different body sizes [18,46].This purposive sampling scheme may limit the generalizability of the findings, despite this study indicating that weight loss was not required to see a reduction in cardiometabolic risk factors.Overall, these studies indicate again that even in the absence of weight loss, a modification of the dietary pattern may improve the presence of cardiometabolic risk factors in women with PCOS.
Protein Modification.
Rather than modifying the CHO content of the diet, the studies (Table 1) modified the protein intake to improve cardiometabolic risk profiles of individuals with PCOS across BMI categories.Two studies were included in this review, with one reducing the intake of animal protein while increasing intake of textured soy protein [75] and the other examining a high-protein diet (>40% of energy intake) [76].While both studies improved markers of cardiometabolic risk [75,76], the limitations should be considered.In the textured soy protein study, all participants were prescribed metformin, regardless of intervention group.Thus, metformin may have influenced the improvements in cardiometabolic risk [75].In the 6-month ad libitum high-protein study, there was a 53% attrition rate [76], which may have influenced the results and indicates that the intervention is not sustainable for this population.Though, overall, both of these studies again highlight that dietary modifications, irrespective of changes in energy, may promote improvement in cardiometabolic risk factors.While both studies studied protein modification, the interventions varied greatly, making it hard to come to any overall conclusions regarding the role of dietary protein to reduce cardiometabolic risk factors in individuals with PCOS.Nonetheless, modification of protein intake, regardless of BMI, may improve cardiometabolic risk factors in individuals with PCOS.
In a unique study design, researchers [77] examined the effect of a high saturated fat, starch avoidant diet (HSF-SA) in individuals with PCOS with obesity (Table 1).Individuals were instructed to consume half of their total energy as saturated fat with restricted amounts of non-starchy vegetables and fruits.After 24 weeks, BMI, percent total body weight, and insulin concentrations were significantly reduced, with no differences in lipid profiles.Although the researchers suggested that a HSF-SA diet can lead to weight loss without adverse effects on lipid profiles in individuals with PCOS with obesity [77], longer term studies are warranted.Additionally, this study lacked a description of the demographic characteristics and a control group.Furthermore, this type of intervention may not be appropriate amongst all BMI groups.

Dietary Patterns
Low-Glycemic Index (GI) Diet.Studies (Table 1) have found a low-GI diet to improve insulin sensitivity [78-80], even when the intervention is designed to be isocaloric [79,80] or when clinically significant weight loss does not occur [78].Individuals across BMI ranges were included in two of these studies [79,80].In one of these studies, when researchers compared an ad libitum low-fat, low-GI diet to a conventional low-fat healthy diet in individuals with PCOS, participants were advised to follow the intervention until 7% of baseline body weight was lost [78].However, only 59% and 50% of participants in the low-GI group and the conventional healthy diet group were able to meet that goal, respectively, perhaps due to the ad libitum nature of the study design [78].Furthermore, the attrition rate was high (49%); participants who dropped out had a higher baseline BMI and higher insulin resistance [78], suggesting that those with a higher prevalence of cardiometabolic risk factors may not be responsive to this type of intervention.Despite a large proportion of participants not achieving the desired weight loss, there were still improvements in insulin sensitivity [78].In other research exploring isocaloric low-GI diet interventions with individuals across BMI ranges, improvements in insulin sensitivity were observed [79,80], indicating that metabolic changes can reduce cardiometabolic risk in the absence of anthropometric changes.Yet these studies suffer from small sample sizes [79,80], and one study did not have a comparison group [79].
Researchers examined the effects of a low-starch, low-dairy diet for eight weeks in ten individuals with PCOS with overweight and obesity [81] (Table 1).The ad libitum diet excluded all grains, beans, pulses, dairy, and sugar.After eight weeks, body weight, BMI, WC, hip circumference, fat mass, fat mass percentage, and fasting insulin concentrations significantly decreased [81].Yet this study presents with several limitations, including a small sample size, lack of control group, and no assessment of pre-intervention dietary intake.Ketogenic Mediterranean Diet.
A ketogenic Mediterranean diet intervention (Table 1) showed initial improvements in cardiometabolic risk profiles, including lipid profiles after 12 weeks among individuals with PCOS with overweight and obesity [82].Researchers found significant reductions in body weight, BMI, fat mass, WC, lean body mass (LBM), glucose and insulin concentrations, HOMA-IR, and lipid profiles, along with improvements in HDL-C concentrations, among individuals with PCOS after the 12-week intervention.The researchers initially described the intervention as eucaloric but later described it as a low-calorie ketogenic diet, making it unclear how the energy intake was modified.Furthermore, the study lacked a description of the demographic characteristics of participants and control group.Additionally, it is unclear if this is an appropriate dietary pattern for individuals with PCOS at a healthy BMI.Ultimately, the long-term effects and sustainably of this type of dietary pattern are unknown.

Eating Behavior
Meal Timings/Frequency.Studies (Table 1) have explored the effects of a restricted feeding period (fasting 4 pm-8 am) [83], Ramadan fasting [86], modification of energy intake timing (high calorie breakfast versus high calorie dinner) [84], and a three or six meals per day pattern [85] for individuals with PCOS.All four interventions were designed without energy manipulation [83][84][85][86], with three of the studies including individuals across BMI ranges [84][85][86].Three of the studies found improvements in cardiometabolic risk factors [83][84][85], with the one quasi-experimental study finding no differences in cardiometabolic risk factors pre-and post-Ramadan fasting [86].Yet in the restricted feeding period study, where participants fasted from 4 pm to 8 am daily, only 20% of participants reported never feeling hungry [83].Feelings of hunger need to be considered when advising patients, as this may limit the long-term sustainability of this type of intervention.A longer study with a control group, larger sample, and larger diversity of participants is needed.
In the study that modified caloric intake timing and only included individuals with a healthy BMI, researchers found significant improvements in cardiometabolic risk factors in the high-calorie breakfast group compared to the high-calorie dinner group [84].The low attrition rate of the study (7% in the breakfast group, 10% in the dinner group) is also a strength and a possible indicator that this intervention is more realistic and sustainable [84].Furthermore, it provides evidence of an intervention for individuals with a healthy BMI and for whom weight loss interventions described in the literature are not appropriate.
Modification of Advanced Glycation End Products (AGEs).
Researchers explored the effect of advanced glycation end products (AGEs) on metabolic profiles in a study that included individuals with PCOS across BMI ranges (Table 1) [87].Participants increased their cooking temperatures during the two-month high AGEs phase and decreased their cooking temperatures during the two-month low AGE phase.Serum AGEs were correlated with insulin concentrations and HOMA-IR during the low AGEs diet, indicating that changes in dietary AGE intake were related to changes in insulin sensitivity.Limitations of the study include no washout period and a high dropout rate (32%).
The variety of interventions altering dietary patterns makes it challenging to identify the most effective dietary intervention for individuals with PCOS.Overall, many of the eucaloric interventions have similar improvements in cardiometabolic risk factors compared to hypocaloric interventions, suggesting that changes in dietary patterns without caloric restriction may promote beneficial changes for individuals with PCOS.Furthermore, many of these changes in the dietary patterns would be appropriate for individuals with a range of BMIs.

Energy Restriction and Macronutrient Distribution
Energy Restriction with Protein Modification.Several studies (Table 1) have looked at restricting energy and modifying protein intake in individuals with PCOS with overweight and obesity.One study included individuals across BMI ranges for whom they modified the estimated energy needs, yet most of the study participants had a BMI greater than or equal to 25 kg/m 2 [91].These energy-restricted with protein modification interventions included a comparison of a hypocaloric diet with protein supplement compared to a hypocaloric diet with simple sugar supplement [88], a hypocaloric high versus low-protein diet [89,91], and a hypocaloric high-protein versus high-CHO diet [92].
While most studies found no significant effect of dietary composition on cardiometabolic risk factors [89,91,92], one study found a hypocaloric diet with a powdered protein supplement to decrease body weight, fat mass, and total cholesterol concentrations compared to a hypocaloric diet with a simple sugar supplement [88].Unfortunately, a decrease in lean body mass [89] and HDL-cholesterol concentrations [88] was reported in two of the interventions.Overall, the results of these interventions need to be interpreted cautiously.All studies had relatively small sample sizes [88,89,91,92], and three lacked a control group [88,89,92] and were short in duration [88,91,92], thus limiting the understanding of the sustainability and long-term effects of these dietary interventions.Furthermore, the lack of participant diversity [89,91] limits the generalizability.Lastly, the studies largely included individuals with overweight and obesity, thus further limiting the generalizability of this intervention to individuals with PCOS across BMI ranges.
Energy Restricted with Carbohydrate/Fat Restriction.
Researchers studied the effect of an energy-restricted diet where two meals per day were replaced with a meal replacement beverage, followed by a 24-week maintenance phase with either a CHO counting (<120 g/CHO/day) or fat counting (<50 g/fat/day) protocol in individuals with PCOS with overweight and obesity [93].While total cholesterol, triglyceride, LDL-C, and C-reactive protein concentrations significantly decreased after phase one, these variables increased during phase two.Thus, there was no difference in these variables from baseline to study completion [93], perhaps highlighting that the cardiometabolic benefits from weight loss on meal replacements alone are difficult to maintain.Weight regain was reported during phase two, but a significant weight loss was maintained from baseline [93].The high attrition rate and weight regain [93] question the sustainability and acceptability of these diets.A large limitation of the study [93] is the lack of diversity in the sample as well as the lack of generalizability to individuals across BMI ranges.

Energy Restriction and Dietary Pattern
Energy-Restricted Dietary Approaches to Stop Hypertension (DASH) Diet.Two studies (Table 1) explored an energy-restricted DASH diet compared with an energy-restricted control diet in PCOS individuals with overweight and obesity [94,95].Significant improvement in weight, BMI, and insulin concentrations were seen in the energy-restricted DASH diet group in both studies [94,95].In addition, one of the studies found the energy-restricted DASH diet to significantly decrease triglycerides and very low-density lipoprotein cholesterol concentrations compared to the control group [94].Thus, the energy-restricted DASH diet demonstrated an ability to improve cardiometabolic risk factor profiles above and beyond energy restriction alone, yet this type of diet may not be suitable for all individuals with PCOS, particularly those within a healthy BMI range.
In addition to the low-GI studies discussed above, studies have examined an energyrestricted, low-GI diet for individuals with PCOS.The low GI interventions included an energy-restricted, low-GI diet [96][97][98] and an energy-restricted, low-GI, high-protein diet [99].Two of the studies included individuals with PCOS with overweight and obesity [96,99].One of the studies included individuals with a healthy BMI (21% of participants), yet all were given the recommendation to reduce caloric intake by 600 kcal/day [97,98].
Researchers found that a hypocaloric diet with modification of both GI and protein content has beneficial effects on cardiometabolic risk factors compared to a hypocaloric diet on its own [99].However, the study modified both the GI and percentage of energy coming from protein, making it unclear which one of those factors, or the combination of both, drove the results.The limitations of these studies, similar to many of the other studies included in this review, include the lack of a control group [97,98], different measures of cardiometabolic risk [96], and the inability to determine what is driving the relationship of the improvement in cardiometabolic risk factors.
Overall, a large variety of dietary interventions have been studied in the research literature.While some of the interventions have limited the energy intake substantially (VLCDs), more modest energy-restricted diets (500 calories/day), as well as changes in dietary patterns without energy restriction (such as, low carbohydrate, high protein, and low glycemic index) and alterations in eating behavior (such as modification of caloric intake timing, time-restricted feeding, and number of meals per day), appear to offer similar benefits compared to greater energy restrictions.Interventions that modified the dietary pattern without energy restriction were found to improve cardiometabolic risk factors in individuals with PCOS across BMI ranges, indicating an approach that might be realistic for most individuals with PCOS.Yet many of the studies suffer from the same limitations including small sample sizes, a short duration of the interventions, a lack of control groups, high attrition rates, and a lack of randomized controlled trials.

Lifestyle Interventions
The research literature has examined lifestyle interventions in the forms of diet (energyrestricted diets, dietary patterns, nutrition education, and energy restriction with dietary patterns) and another behavioral modification (e.g., exercise or cognition) for individuals with PCOS, largely focusing on individuals with overweight and obesity.The findings are summarized in Table 2.
Overall, energy restriction plus exercise has been shown to decrease weight [104][105][106], BMI [101,102,104,105], WC [101,102,104,106,107], hip circumference [104], body fat [105], fat-free mass [105], lean body mass [101,102], blood pressure [104,106], HOMA-IR [106,107], glucose [106], insulin [106], triglycerides [104], total cholesterol [101,102,106], and LDL-C concentrations [104,106], and to improve HDL-C concentrations [107] in individuals with PCOS.The reduction in lean body mass, even in the presence of exercise, warrants further study.Additionally, some of these initial changes may be difficult to maintain.After three months of an energy-restricted (600 kcal/day deficit) and physical activity (30 min, two to three times per week) intervention, individuals with PCOS had significantly lower body weight, BMI, WC, hip circumference, WHR, HOMA-IR, LDL-C, and insulin concentrations compared to baseline [104].Yet at six months, the changes in insulin concentrations and HOMA-IR were no longer significant, while significant decreases in systolic blood pressure and triglyceride concentrations emerged [104].Further study of the long-term effects of lifestyle interventions is needed.
In two studies [100,103], participants were stratified by ovulation status.Participants who resumed ovulation had decreased body weight [100,103] and abdominal fat [100].Yet these two studies differed in their intervention, with one being a six-month energy restriction of at least 500 kcal/day with individualized exercise programs [100] and the other comparing a structured exercise training program or a higher protein diet with 800 kcal/day deficit [103].These results are difficult to compare with other studies that do not stratify their results based on ovulation status.Additionally, in one of these studies [103], participants self-selected into their intervention group, which may have introduced selection bias into the study.
Researchers looking at diet only compared with diet and aerobic exercise or diet and combined aerobic-resistance exercise found that the addition of a structured exercise component did not improve clinical and biochemical cardiometabolic risk preferentially over a diet only intervention but led to significantly greater improvements in anthropometric measures [106].Thus, having both diet and exercise components may have larger improvements in cardiometabolic risk profiles in individuals with PCOS than either diet or exercise alone.Yet these studies focused on individuals with PCOS with overweight and obesity, making them less generalizable to individuals with PCOS across BMI ranges.

Dietary Patterns and Exercise
One study included in this review (Table 2) looked at changes in dietary patterns and exercise in improving cardiometabolic risk in individuals with PCOS across BMI ranges.Researchers compared a low-glycemic index pulse-based diet, high in beans and legumes, or the therapeutic lifestyle change diet, focused on increased fiber and decreased saturated fat and cholesterol intakes, in individuals with PCOS for one year [108].Both of these dietary interventions were paired with aerobic training programs.Initial changes to cardiometabolic risk included a decrease in BMI, WC, systolic blood pressure (SBP), glucose, insulin, and total cholesterol concentrations in both the pulse-based and therapeutic lifestyle changes groups.The pulse-based group initially had a significantly larger decrease in DBP, insulin area under the curve, triglyceride, LDL-C, and total cholesterol/HDL-C ratio concentrations compared to the therapeutic lifestyle changes diet.At 12 months, only the increased HDL-C concentrations and lower total cholesterol/HDL-C ratio stayed improved in the pulse-based group.Other improvements in cardiometabolic risk returned to pre-intervention levels [108].Unfortunately, this study had a high attrition rate and poor response rate to dietary recalls [108].Additionally, although the study protocol included individuals with PCOS across BMI ranges, the baseline mean BMI was 32.5 ± 8.4 kg/m 2 and 33.3 ± 9.0 kg/m 2 for the pulse-based and therapeutic lifestyle changes groups, respectively [108].Thus, greater understanding of the effect of this type of lifestyle change in individuals with PCOS of all body sizes is needed.

Nutrition Education and Exercise
Studies that combine nutrition education and exercise have been conducted for individuals with PCOS with overweight and obesity (Table 2).The two studies included in this review provided nutrition education through weekly seminars paired with endurance and resistance training [109], or group and individual nutritional counseling paired with exercise counseling in individuals with PCOS among overweight and obese BMI categories [110].Researchers examining the effects of the weekly seminars paired with exercise found a decrease in insulin concentrations, despite no significant decrease in BMI.This highlights a possible cardiometabolic benefit of a nutrition education and exercise intervention in the absence of weight loss [109].
In a similar study examining individual or group diet and exercise counseling, those participants who resumed ovulation had a decrease in WC, central abdominal fat, and insulin concentrations, with an increase in insulin sensitivity [110].Researchers did not assess the difference in results between group and individual counseling [110], limiting our understanding of which intervention delivery method may be more effective.Additionally, the participants in these two studies were all categorized as overweight or obese by BMI.Furthermore, the small sample sizes of both of these interventions are limitations [109,110].

Energy Restriction, Dietary Pattern, and Exercise
Energy-Restricted Mediterranean-Style Diet, Low-Glycemic Load, and Exercise.Using a quasi-experimental design, researchers explored a Mediterranean-style, lowglycemic load, hypocaloric diet with physical activity recommendations for 12 weeks in individuals with PCOS and overweight and obesity [111].The dietary pattern comprised 25% protein, 25% fat, and 50% CHO and was designed to be low-fat, with moderate-tohigh fiber and an energy deficit of 500 kcal/d.Researchers found decreased BMI, WC, body fat percentage, systolic blood pressure, diastolic blood pressure, HOMA-IR, glucose, insulin, total cholesterol, LDL-C, triglycerides, C-reactive protein concentrations, and triglycerides/HDL-C ratio [111].Yet there was no comparison group, compliance with the physical activity regimen was not assessed, and researchers only included participants with overweight or obesity.Thus, the appropriateness of this lifestyle intervention for individuals with PCOS across all BMI categories cannot be determined.
Energy-Restricted High Protein, Low Carbohydrate Diet and Exercise.
Researchers assessed a 3-month energy-restricted, high-protein, low-carbohydrate diet and aerobic physical activity in individuals with PCOS with overweight and obesity [112].The intervention consisted of an unspecified amount of energy restriction for weight loss in addition to following a high-protein, low-carbohydrate (40% CHO, 30%, 30% protein) dietary pattern with 45 min of aerobic activity two to three times/week [112].Postintervention body weight, BMI, and insulin concentrations significantly decreased [112], highlighting potential cardiometabolic benefits of this intervention.Yet similar to the dietary interventions that combined dietary patterns and energy restriction, it is unclear if one aspect is driving the results.Furthermore, the energy restriction implemented in this lifestyle intervention would not be suitable for individuals with PCOS with a healthy body weight.

Energy Restriction and Cognition
Two studies included in this review examined energy restriction combined with a cognitive behavior therapy (CBT) intervention in individuals with PCOS with overweight and obesity (Table 2).In one study, when researchers incorporated CBT as an adjunct to lifestyle counseling, they found significant improvements in weight loss compared to standard lifestyle counseling alone [113].Additionally, participants in the CBT group were significantly more likely to meet their exercise goal and keep their weekly food diary than those solely in the lifestyle modification group [113].These results highlight the potential of psychological interventions in improving cardiometabolic outcomes.Yet this study had a high attrition rate for the CBT group, a small sample size, only included participants with an overweight or obese BMI, and was of the shortest duration (8 weeks) of the lifestyle interventions included in this review.
A retrospective analysis of a lifestyle intervention of individuals with PCOS with obesity incorporated a VLCD of approximately 600 calories per day and a behavior change program informed by CBT [114].After 12 weeks, the PCOS group had lower body weight compared to baseline [114].This study was limited in that it was a retrospective analysis of a lifestyle intervention, had a high attrition rate (73%), did not compare dietary intake data, and only included participants with PCOS with obesity [114].
Overall, considering the lifestyle interventions included in this review, the combination of dietary changes with exercise appears to confer an additional cardiometabolic benefit than just one component alone [101][102][103]109], and at times, even in the absence of changes in weight or anthropometric measures [103,109].The lifestyle intervention research indicates that incorporating both diet and exercise into a well-rounded intervention may lead to greater improvements in cardiometabolic risk profiles.
Yet limitations of the lifestyle interventions should be considered.Many studies lacked a comparison group [100,105,[110][111][112], had a small sample size [105,109,110,112,113], suffered from high attrition rates [100,108,113], and did not report on the length of duration [105].Furthermore, other studies had participants self-select the intervention group [103], introducing selection bias and affecting internal validity.Furthermore, adherence to the lifestyle intervention was not always measured [111].The external validity of the studies is limited due to the lack of diversity in participants [100], and many of the studies were limited to individuals who were classified as overweight or obese.Future lifestyle intervention research that looks at both the psychological aspects of behavior change, as well as the long-term maintenance of cardiometabolic risk improvements for individuals across BMI ranges, is needed.Compared to the other two groups, the energy restricted group showed the following: • ↓ body fat (pre: 45.5 ± 3.6 kg, post: 44.0 ± 6.0 kg; p < 0.05), HOMA-IR d (pre: 3.6(3.0-6.9),post: 2.9(2.2-3.6);p < 0.05), and LDL-C e (pre: 2.8 ± 0.8 mmol/L, post: 2.3 ± 0.9 mmol/L; p < 0.05).
Compared to the exercise group, both energy restricted and energy restricted plus exercise groups showed the following:    Compared to control group, at 6 months, PCOS group showed the following: • ↓ DBP q (−5.2 mmHG, 95% CI: −10.Compared to the TLC group, at 6 months, the pulse-based group showed the following: • ↓ TC/HDL-C ratio was maintained (p = 0.02).

Summary
Overall, a variety of lifestyle interventions can be utilized to reduce the prevalence of cardiometabolic risk factors in individuals with PCOS.In this review, randomized control trials were limited: only 13 of the dietary and 6 of the lifestyle interventions were randomized interventions.Additionally, many of the intervention studies lacked control groups, and most studies focused on weight loss and excluded individuals classified within a healthy BMI range.Only 11 of the dietary and 1 of the lifestyle interventions included participants with a healthy BMI in their inclusion criteria.Furthermore, only 16 of the dietary and 3 of the lifestyle interventions did not involve energy restriction.Yet studies that modified dietary patterns without a caloric deficit [72][73][74][75][76][77][78][79][80][81][82][83][84][85]87,108] saw improvements in cardiometabolic risk factors.Thus, less restrictive dietary approaches may be better suited for this population, as they can be applied irrespective of weight and disordered eating history.This finding is supported by the recommendations from the 2023 International Evidenced-Based Guidelines for the Assessment and Management of PCOS that indicate there are benefits to a healthy lifestyle even in the absence of weight loss [1].
Furthermore, the sustainability of weight loss interventions has been questioned [55][56][57], and weight cycling has been identified as an independent risk factor for cardiovascular disease [58,59].Several weight loss interventions included in this review had high attrition rates [63][64][65]89,92,93,100], signaling that the interventions may not be sustainable in realworld scenarios.This finding, compounded with the disordered eating and poor body image in the PCOS population [50][51][52][53][54], highlights the importance of a more sustainable lifestyle intervention that is not solely focused on reducing energy intake for individuals with PCOS.Due to the possible difficulty to maintain weight loss long term, focusing on dietary patterns is a strategy to improve health outcomes that may be more sustainable and better meet the psychological needs of this population.Dietary patterns, such as low carbohydrate, high protein, low glycemic index, as well as alterations in the eating behavior including time-restricted feeding, modification of caloric intake timing, and the number of meals per day, should be further explored in this population among individuals across BMI ranges.
Additionally, most studies rely on BMI to identify participants, despite a higher prevalence of cardiometabolic risk factors among all individuals with PCOS, regardless of BMI [19,26].This largely limits our understanding of the best lifestyle practices for individuals with PCOS across body sizes.Expanding our research recruitment outside of medical centers, where individuals with worse clinical presentations may be prevalent [4,18,39], should be prioritized.Moreover, a more robust screening should be conducted to determine metabolic risk, as a singular measure of body size is a flawed diagnostic criterion of one's overall metabolic health.Individuals who are classified into overweight or obese BMI categories may be metabolically healthy, just as much as individuals classified into a healthy BMI category could be metabolically unhealthy [115].In support of this, the 2023 International Evidenced-Based Guidelines discuss weight stigma in PCOS.The guidelines acknowledge that while a higher weight and BMI is a risk factor, it is only one indicator of health and other factors should be considered.Furthermore, the guidelines recommend offering options for weight-inclusive care that is focused on promoting lifestyle change without focusing on intentional weight loss [1].

Strengths and Limitations
To our knowledge, this review is the first to summarize the dietary and lifestyle strategies to reduce cardiometabolic risk in individuals with PCOS across body sizes.Additional, the strengths include the inclusion and discussion of a wide variety of dietary and lifestyle interventions to mitigate cardiometabolic risk in individuals with PCOS.Furthermore, this review included studies that examined lifestyle approaches for individuals with PCOS across BMI ranges, increasing the applicability of the results to individuals with PCOS across body sizes.Lastly, a comprehensive search strategy was used and strict exclusion criteria were followed in an attempt to minimize selection bias.The limitations of this review include that only two databases were searched and it did not include conference proceedings, abstracts, government publications, or theses.The studies incorporated in this review also utilized different diagnostic criteria for PCOS.The current recommendations from the 2023 International PCOS guidelines are to use the International Guideline diagnostic criteria, which builds upon the Rotterdam criteria [1].Finally, the results of these studies were not systematically reviewed and analyzed.

Implications for the Practice
Currently, few of the included interventions have explored the condition through a more holistic, biopsychosocial lens.Overlooking the psychological and social factors may make interventions less sustainable and ultimately, not appropriate for this population.Individuals with PCOS report being largely unsatisfied with the lifestyle recommendations that they receive [116][117][118][119] and believe that that the psychological aspect of PCOS is largely ignored [118].Recent American Heart Association recommendations highlight the clear association between psychological well-being and cardiovascular disease, demonstrating how improvements in psychological well-being can lead to improvements in cardiovascular health.Conversely, detriments to psychological well-being can negatively affect cardiovascular health [120].In support of this, recent work in women with overweight and infertility suggests that childhood adversity is associated with poorer health behaviors [121].
There is likely no one-size-fits-all approach to managing PCOS.Thus, a thorough understanding of an individual's cardiometabolic risk profile, their weight and disordered eating history, level of central adiposity, dietary preferences, lifestyle behaviors, previous experiences with weight loss attempts [122], and potential harm of weight cycling should all be considered when approaching the care of individuals with PCOS.Attention should be given to the psychological components of weight stigma, living in a larger body, and PCOS.
While there does not appear to be one type of lifestyle that is preferable for PCOS, overall, clinicians should promote the adoption of healthy lifestyle behaviors that include adequate physical activity and a varied, flexible diet that meets nutritional needs, individual preferences, and cultural considerations, while avoiding unduly restrictive, unbalanced diet patterns [1].Overall, a better understanding of what individuals with PCOS want out of their care and the tailoring of their care to meet their individual preferences and goals is needed.

Implications for the Research
While a great deal of research has been conducted on this topic, it is of variable quality and with a great variety in the type of interventions, limiting our ability to come to strong conclusions.Future research could utilize the data more efficiently through prospectively planned pooled analyses.This collaborative approach would allow researchers to combine efforts to elucidate important areas where information is missing.The most recent International Evidence-Based Guidelines may be a good starting point to identify pertinent research questions.
Additionally, it is important to improve the detection of PCOS in the general population.If detection continues to be limited to risk groups with overweight or obesity and/or infertility, individuals with PCOS with a normal body weight may be missed.In an effort to improve the diagnosis of PCOS, the 2023 International Evidence-Based Guidelines has recommended that serum anti-Mullerian hormone (AMH) could be used in lieu of ultrasound for defining PCOS, in conjunction with the pre-existing diagnostic algorithm [1].Overall, improving detection may allow for an overall better understanding of the spectrum of disease which can guide future intervention strategies.In addition, efforts should be made to include study participants across body sizes to understand their burden of disease, as well as appropriate lifestyle strategies to mitigate cardiometabolic risk.
Lastly, the role of genetics and epigenetics in PCOS needs to be further explored, as genetic variation appears to play an important role in the pathogenesis of PCOS [123].Ani-mal studies have shown that epigenetic changes in utero can perpetuate PCOS phenotypes across multiple generations [123].Understanding the role of genetics and epigenetics can aid in elucidating the etiologies of PCOS, the development of targeted therapies, and the transition toward precision medicine for PCOS.
Overall, this review highlights the critical need for a more sustainable lifestyle intervention that meets the needs of individuals with PCOS of varying body weights.Future research is needed that focuses on improving cardiometabolic risk factors through lifestyle approaches that simultaneously incorporate the biological, psychological, and social considerations of this unique population to identify an approach that is realistic, sustainable, and enjoyable.
3 to −0.1; p = 0.04).Age.Non-randomization in the post hoc analysis.Dietary Pattern and Exercise Pulse-Based Diet with Aerobic Training Program

Table 1 .
Dietary intervention studies to improve cardiometabolic risk in individuals with polycystic ovary syndrome.
•No sig.difference in body weight, BMI, glucose, or lipid profiles.
2; p < 0.05).Decreased; † Included participants aged 14-35 years, mean age was 22.72 ± 5.68 years; ‡ included participants aged 17-38 years; a PCOS: Polycystic Ovary Syndrome; b BMI: Body Mass Index; c OGTT: Oral Glucose Tolerance Test; d HOMA-IR: Homeostatic Model Assessment of Insulin Resistance; e TC: Total Cholesterol; f TG: Triglycerides; g WC: Waist Circumference; h HC: Hip Circumference; i AUCins: Area Under the Curve Insulin; j CRP: C-Reactive Protein; k TFM: Total Fat Mass; l TFFM: Total Fat-Free Mass; m LDL-C: Low-Density Lipoprotein Cholesterol; n HDL-C: High-Density Lipoprotein Cholesterol; o CHO: Carbohydrate; p ADA: American Diabetes Association; q MUFA: Monounsaturated Fatty Acids; r VLDL-C: Very Low-Density Lipoprotein Cholesterol; s QUICKI: Quantitative Insulin-Sensitivity Check Index; t GI: Glycemic Index; u GL: Glycemic Load; v BF%: Body Fat Percentage; w LBM: Lean Body Mass; x VAT: Visceral Adipose Tissue; y VFA: Visceral Fat Area; z AUCglu: Area Under the Curve Glucose; aa HOMA-B: Homeostasis Model Assessment of Beta Cell Function; bb AGES: Advanced Glycation End Products; cc SBP: Systolic Blood Pressure; dd DASH: Dietary Approaches to Stop Hypertension; ee DBP: Diastolic Blood Pressure; ff WHR: Waist/Hip Ratio.

Table 2 .
Lifestyle intervention studies to improve cardiometabolic risk in individuals with polycystic ovary syndrome.
l BP: Blood Pressure; m BF%: Body Fat Percentage; n FFM: Free-Fat Mass; o SBP: Systolic Blood Pressure; p WHR: Waist-to-Hip Ratio; q DBP: Diastolic Blood Pressure; r TLC: Therapeutic Lifestyle Changes; s AUCins: Area Under the Curve Insulin; t QUICKI: Quantitative Insulin-Sensitivity Check Index; u CBT: Cognitive Behavior Therapy; v VLCD: Very Low-Calorie Diet.