During the month of Ramadan, Muslims are required to abstain from smoking, sexual intercourse, eating and drinking, from dawn until nightfall. The average duration of the daytime fast depends on the date and the place of residence [1
], since the Muslim calendar follows the lunar system and each month moves through the solar seasons. Some researchers consider this practice a model of intermittent fasting, characterised by the sudden introduction of modifications in dietary habits [2
]. In general, Muslims have two meals during the night, one when the fast is broken, shortly after sunset, and the other just before sunrise. This change in eating schedules also affects other activities of daily life [3
The effects of Ramadan on nutritional health have been widely studied in countries with a Muslim majority, but few such studies have been undertaken with respect to women in a Western context, although in these settings, too, it is women who are mainly responsible for family care [4
]. Moreover, women are usually more vulnerable to certain pathologies, especially those related to nutrition [5
For many years, obesity has been a major problem worldwide, even in European countries where the Mediterranean diet is deeply rooted. For example, in Spain, levels of obesity have risen throughout the population, but especially among adult women [6
In view of these considerations, together with forecasts of continuing rises in overweight-obesity [7
] and taking into account the known association between visceral adipose tissue and cardiovascular health [8
], the present community-bases nursing study was undertaken to determine the prevalence of overweight and obesity in a group of Muslim women living in a Western society. The study consists of an analysis of nutritional habits, of compliance with recommendations for micronutrient and macronutrient intake, and of whether the observance of Ramadan strictures is associated with variables related to cardiovascular risk.
2. Materials and Methods
2.1. Study Design and Sampling
This follow-up cohort study was conducted on a female Muslim population resident in Melilla, a Spanish city on the coast of North Africa. The sample initially consisted of 62 women, aged 18–61 years. All participants were Muslim women, of legal age, who voluntarily observed the Ramadan precepts. Women with a chronic or acute disease, or who were pregnant or had a metal prosthesis were excluded. Figure 1
shows the flow chart for the sessions conducted.
2.2. Data Collection
In accordance with the calendar for Ramadan during the study period, the first session took place one month before the start of the fast. The second session was held one week before the start of Ramadan, the third in the last week of Ramadan and the final one, three months after Ramadan had ended. In Session 1, each participant was given a dietary record to be completed before the start of Ramadan, and anthropometric and body composition parameters were measured and recorded. In Session 2, these dietary questionnaires were collected, those to be completed during Ramadan were handed out, and the second measurement and recording of anthropometric and body composition parameters was performed. This process was repeated in Session 3, and in the final session, the last measurement and recording of anthropometric and body composition parameters was carried out. Of the 62 women who were given the dietary record to be completed during the corresponding moments of the study, only 45 delivered the two records completed in full. Thus, the loss to study was 27.4%. However, there is no evidence that the loss of these data was related to the nutritional status of the participants. We suggest that this reluctance to participate might have arisen from the study design and/or the characteristics of the religious precepts studied.
This study was conducted in full accordance with the guidelines and ethical principles for medical research in human beings established by the World Medical Association in the Declaration of Helsinki (Finland, 1994), and as reviewed in successive assemblies, the most recent of which was the 64th General Assembly, held in Fortaleza (Brazil) in October 2013. All participants were informed in detail about the study goals and characteristics, and gave signed informed consent to take part. Furthermore, in accordance with the General Regulations on Data Protection and with Organic Law 3/2018, of 5 December, on the protection of personal data and digital rights, data confidentiality was assured; the participants’ anonymity was protected by the use of codes. Moreover, these data were used solely for the scientific purposes presented.
2.3. Anthropometric Evaluation and Body Composition Analysis
Anthropometric variables were measured following the protocol of the International Society for the Advancement of Kinanthropometry [9
]. All variables were measured at the same time of day, between 9 a.m. and 12 noon, and by the same person. The participants were asked to attend without having eaten beforehand, wearing comfortable clothes, with no metal objects in direct contact with the skin, with an empty urinary bladder and without having practiced intense physical exercise in the previous twelve hours. The following anthropometric variables were studied: total body weight (BW), height, body mass index (BMI), waist circumference (WC), waist/hip ratio (W/Hp) and waist/height ratio (W/Ht). Waist and hip circumferences were measured with a flexible, non-extensible Seca®
tape measure, with an accuracy of 1 mm. The waist circumference was measured at the midpoint between the lower rib margin and the iliac crest, with the abdomen relaxed. The hip circumference was measured at the level of maximum circumference of the buttocks. Each perimeter was measured in triplicate by the same observer, and the mean value was taken. The W/Hp ratio was calculated by dividing the waist circumference (cm) by the hip circumference (cm). For this ratio, a score <0.8 was considered within the range of normal values. The W/Ht ratio was calculated by dividing the waist circumference (cm) by the height (cm). For this ratio, a score of 0.4–0.5 was considered normal.
Height was measured using a portable TANITA®
stadiometer, with the participant standing upright, with her head oriented according to the Frankfort plane and with the trunk and pelvis in continuous contact with the vertical branch of the stadiometer. The horizontal branch was then applied to the top of the head. From these weight and height measurements, the BMI was calculated to categorise the participant as normoweight, overweight or obese in accordance with the criteria established by the World Health Organisation (WHO) [10
In addition to the above, a body composition study was conducted using a TANITA® SC-330 body composition analyser, which is self-calibrating and has an accuracy of ±100 g. This apparatus was also used for weight estimation. The following body composition variables were determined: percentage of fat mass, total fat mass, lean mass, muscle mass, percentage of water content, total water content, visceral fat and bone mass.
2.4. Food Consumption
Dietary intake was determined using a 72-h dietary record, in which the participants noted the types and amounts of food consumed, and the procedure used for food preparation. To maximise the precision of the quantities recorded, each participant was given an information sheet with equivalents and other practical indications for use in the home.
The dietary recommendations proposed by the Spanish Society of Community Nutrition (SENC) in 2011 [11
] and the WHO in 2008 [12
] were used to assess the compliance with recommendations for micronutrient and macronutrient intake of Muslim women in each session.
2.5. Statistical Analysis
All statistical analyses were performed using IBM SPSS software v.24 (SPSS Inc., Chicago, IL, USA). For the descriptive analysis, the mean and standard deviation were calculated for each quantitative variable, while the qualitative variables were described by proportions. All variables were assessed in each of the four study sessions, which were compared by a one-way ANOVA. Student’s t-test (with Levene’s test for the equality of variances) was applied for the variables that presented a normal distribution, and, otherwise, the Wilcoxon test was used. The normality of the distributions was verified using the Shapiro-Wilk test.
The effect of fasting during Ramadan (Sessions 2 and 3) was observed using the Wilcoxon test for paired samples. As some values were highly dispersed, an analysis of the medians of the variables was also conducted, before and during Ramadan. Finally, to determine the possible influence of fasting on cardiovascular risk, an analysis of odds ratios, with 95% confidence intervals, was carried out, using a logistic regression model adjusted for the present age and for earliest age on starting observance of Ramadan. In every case, the level of significance assumed was p < 0.05.
The BMI is the most widely-used parameter to define and classify people as overweight and obese. However, body composition techniques provide a more realistic approximation of these concepts [13
]. Accordingly, the present study also includes bioimpedance analysis. In addition, measures of central adiposity are obtained, to evaluate the possible effects of Ramadan on cardiovascular health.
Our results show that BMI values fell during Ramadan, which corroborates previous research in this area, conducted in different countries [14
]. The prevalence of obese women during the final week of Ramadan also fell, which is in consonance with the decrease of the percentage of body fat and visceral fat also observed during the final week of Ramadan. Despite this slight decrease of obesity prevalence, the values of W/Hp and W/Ht did not suffer any change, and the levels were above the normal values. In relation to the changes in body fat that are associated with fasting, some authors have affirmed that a loss of body weight is always accompanied by a corresponding reduction in body fat. Thus, in a study carried out in Sanliurfa (Turkey), a significant reduction was observed in the percentage of body fat and visceral fat, according to bioimpedance results and the waist/hip ratio [18
]. Another investigation, in Indonesia, also measured a loss of body fat. In this case, however, the reduced W/Hp at the end of the fasting period was not significant [19
]. In the present investigation, a significant decrease was observed in the percentage of body fat and visceral fat obtained by bioimpedance, but not in the anthropometric measurement of central adiposity. Moreover, unlike the above-mentioned studies, in our participants the W/Hp and W/Ht ratios were always above the recommended values.
In addition to dietary factors, the participants’ smoking and physical activity habits were considered. In this respect, none of the women in our study were smokers, and all claimed to have maintained the same level of physical activity during Ramadan as in the rest of the year. The dietary records obtained in Sessions 2 and 3 revealed a certain imbalance in the intake of micronutrients and macronutrients. In relation to the intake of micronutrients, a notable finding is the deficit of two vitamins that are essential for adults (according to a study of nutritional objectives for the Spanish population) [11
], namely folic acid and vitamin D. Although by the end of Ramadan mean levels of folic acid had increased significantly, the dietary record obtained in Session 2 indicates a daily intake below the recommended 400 μg/day for women aged 14–70 years [11
]. Similarly, the intake of vitamin D was well below the recommended 10 µg/day throughout the study [11
]. In this respect, the increasing presence of obesity in the population, the use of sunscreen and the decreased consumption of dairy foods all tend to provoke vitamin D deficiency, despite the many hours of sunshine received in this part of Spain [20
Regarding the minerals related to bone health, the participants’ dietary intake of phosphorus was high, both in Session 2 and in Session 3. Significantly, a high intake of phosphorus and a low intake of calcium are both risk factors for inadequate bone mineralisation. For this reason, it is normally recommended to limit the consumption of processed foods, which are the main source of inorganic phosphates [21
]. In addition, hyperphosphataemia is reported to have a negative impact on cardiovascular health [22
Another mineral that presented levels of dietary intake higher than the dietary recommendations [11
], especially during Ramadan, was potassium. This may be due to the substitution of salt by potassium chloride, which is a widespread practice in the preparation of processed foods, as a means of preventing arterial hypertension. However, high levels of sodium intake were also recorded in Sessions 2 and 3. The excessive consumption of salt (sodium chloride), in addition to its widely known prejudicial effects, favours microvascular endothelial inflammation, anatomical remodelling and other functional abnormalities, even in persons with normal blood pressure [23
Regarding the intake of macronutrients, the dietary records reveal an imbalance in the caloric profile in Sessions 2 and 3, with lipids constituting the main source of energy, to the detriment of carbohydrates, especially during the final week of Ramadan. These data differ significantly from the recommendations by the SENC [11
]. In our study, the intake of vegetable fibre was significantly augmented during Ramadan, and the levels were above the dietary recommendations [11
]. The decreased intake of total cholesterol recorded at the end of Ramadan is a positive trend. Nevertheless, the mean values recorded remained above the recommended level [11
]. These findings are consistent with previous dietary research carried out in Spain, such as the ENIDE study [24
] and the Food Consumption Panel [25
]. Similar results were reported by the ANIBES study, which recorded a dietary imbalance in women of all age groups, but especially among older women [5
]. However, in none of these previous studies was the participants’ religion taken into consideration. On the other hand, and despite the influence that religion may exert on nutritional habits, a relevant consideration is that the Muslim women in our study reside in a Western European context.
The study results we report highlight the presence of various cardiovascular risk factors among the participants, chiefly overweight/obesity and high waist/hip and waist/height ratios, throughout the study period. Moreover, the weight loss observed during Ramadan is not a protective factor, since this loss is fully recovered three months later. These findings are in line with previous reports, according to which the average weight loss during Ramadan is just over one kilogram, which is subsequently recovered or even increased [26
]. Another study concluded that Ramadan observance had a neutral effect on health, in view of the ephemeral nature of the changes recorded [28
]. In addition, we report an association among the observance of Ramadan and the presence of elevated W/Hp ratio and visceral fat, variables which have been shown to be associated with cardiometabolic risk factors [29
]. These results are not in agreement with those of Silveira et al. [30
] and Yang et al. [31
], who reported that intermittent fasting had positive effects on reducing cardiovascular risk factors in obese women. These differences are probably due to the non-compliance with dietary recommendations by the participants of our study, which have been previously discussed.
Regarding the dietary habits observed, only the increased potassium intake represents a special health risk during Ramadan. However, it is unknown whether the elevated potassium levels associated with increased dietary intake have adverse effects among the general population since, to date, the only studies conducted in this respect have focused on adults with normal renal function [32
]. Nevertheless, our findings regarding the dietary habits of the participants corroborate the generalised trend away from the Mediterranean diet in many European countries, despite the evidence of its importance in preventing cardiovascular risks [33
A relevant consideration is the geographic context of the city of Melilla, which is subject to the cultural influence of neighbouring countries in the Middle East and North Africa. In these regions, it is socially acceptable, or even desirable, for women to be overweight [34
]. The possible influence of Arab culture might be apparent in the fact that more than half of the women in our study perceived themselves as having normal weight, despite the objectively high values recorded.
In summary, all of the participants were overweight or obese. Although their BMI values decreased during Ramadan, they had returned to baseline three months later. At no stage of the study did the participants comply with the recommendations for the intake of macronutrients and micronutrients, but the imbalance was heightened during Ramadan. For this reason, it is necessary to ensure healthy fasting during Ramadan by promoting a balanced intake of macronutrients and micronutrients.
Among the strengths of our study, to our knowledge it is pioneering in the sense that no previous investigation has been made of the dietary impact of fasting, as a feature of religious observance by Muslim women before, during and after Ramadan. Among its limitations, it was not possible to analyse the participants’ lipid profile during Ramadan, as almost all of them stated that drawing a blood sample might invalidate their fast. Another limitation was that the sample size of our study is low.