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ORIGINAL ARTICLE
Year : 2018 | Volume
: 37
| Issue : 3 | Page : 133-140
Comparing the effects of short-term fasting therapy and low-calorie diet on anthropometric and leptin measures among obese or overweight persons: Randomized controlled trial
Prashanth Shetty1, Sujatha Dinesh1, Naveen Gowrapura Halappa2, T Rajany3
1 Department of Natural Therapeutics, SDM College of Naturopathy and Yogic Sciences, Dakshina Kannada District, Karnataka, India
2 Department of Yoga, JSS Institute of Naturopathy and Yogic Sciences, Coimbatore, Tamil Nadu, India
3 Center for Yoga and Naturopathy Research and Development, SDM College of Naturopathy and Yogic Sciences, Dakshina Kannada District, Karnataka, India
Correspondence Address:
Dr. Naveen Gowrapura Halappa
JSS Institute of Naturopathy and Yogic Sciences, Coimbatore, Tamil Nadu
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/asl.ASL_1_18
Background: Preclinical and clinical studies have shown the importance of calorie restriction diet in cardiovascular risk factors such as weight. In this study, our objective is to compare the Naturopathic short-term fasting therapy with low-calorie diet on anthropometric and leptin measures among obese and overweight persons. Materials and Methods: Obese and overweight subjects (n = 84, 59.52% females) with Body Mass Index (BMI) ≥25 were randomized into fasting therapy intervention (n = 42) and a low-calorie diet intervention (n = 42). After a written informed consent, the fasting therapy and low-calorie diet intervention group underwent a very low-calorie diet (288-904 kcal) and a low-calorie diet (1234 kcal) respectively for 10 days. Subjects in both the groups were assessed with serum leptin levels and anthropometric parameters such as BMI, weight, waist circumference (WC), hip circumference (HC) and waist-hip ratio (WHR) at the baseline and after 10 days. Results: Within-group comparison showed both the groups did better in all the parameters. However, greater changes were observed in the fasting group as compared to the low-calorie diet group. Changes in BMI, weight, HC and WC were significantly different in the two groups (P < 0.05), except for serum leptin (P > 0.05). Conclusions: The findings support that, both short-term fasting therapy and a low–calorie diet are beneficial in reducing leptin and anthropometric parameters among obese or overweight subjects. However, long-term adherence of weight loss with these interventions need to be tested with future studies.
Keywords: Fasting therapy, leptin, low-calorie diet, naturopathy, very low-calorie diet
According to an estimation in 2014, obesity affects 600 million people and overweight affects 1.9 billion adults globally and the prevalence rate of obesity has doubled since 1980.[1] A study in adult population from the state Uttarakhand, a northern state of India has reported prevalence of obesity as 13.9% in females and 11.1% in males.[2] Etiology of obesity has been complex and incompletely understood. Genetic, environmental and psychological factors are known to play their roles. However, excessive intake of a high-calorie diet and a lack of physical activity are mainly responsible for obesity.[3],[4] The role of Leptin and Ghrelin hormones and genetic susceptibility have been implicated in the pathophysiology of obesity. It is known that obese individuals may gain resistance to Leptin.[5] Likewise, the role of adipose tissue is important in the regulation of weight, inflammation and metabolic functions because of the secretion of cytokines.[6] Leptin is secreted by adipocytes, which is a product of ob-gene. The blood levels of cytokine leptin are elevated in obese humans and it was positively correlated with body fat percentage.[7] Interestingly, leptin levels are estimated to be higher in Asian Indians than Creoles and Europeans, suggesting a potential metabolic risk factor.[8]
Conventional biomedicine has been useful in managing weight, however, it comes with many side effects.[9],[10],[11] Due to this, people have been drifting to complementary and alternative systems of medicine (CAM) to find a solution for this problem. Among Naturopathy and Yoga treatment modalities, therapeutic fasting therapy, raw diet therapy and a naturopathic based low-calorie diet have been practiced by Indian and Western naturopaths.[12],[13],[14],[15] Studies suggest low and a very low-calorie diet are effective in weight reduction.[16],[17] A recent systematic review and meta-analysis reported reductions in body weight, BMI, and systolic blood pressure, and reductions of marginal clinical significance in body fat, waist circumference, HbA1c, fasting glucose, fasting insulin, and diastolic blood pressure after a liquid meal.[18] Another study with a naturopathic fasting therapy on healthy controls showed a significant reduction in weight and BMI in comparison with routine diet group.[19] An earlier study in an integrative medicine ward suggested feasibility of juice fasting for 7 days.[20] Although there are studies on the beneficial effects of naturopathic based fasting therapy on weight reduction in healthy volunteers, there have been no prospective studies for establishing the effects of naturopathic principles based therapeutic fasting therapy and low-calorie diet in obese/overweight persons till date. Also, clinical observation in a Naturopathy hospital indicated that these two diets are beneficial in overweight and obese individuals. We have felt there is a need to elucidate the effects of Naturopathic principles based therapeutic fasting therapy against a Naturopathic low-calorie diet, on leptin and anthropometric measurements on obese/overweight persons. Therefore, we hypothesized that a 10 day fasting therapy would result in significant changes in these parameters than the naturopathic low-calorie diet group.
Materials and MethodsStudy participants
Obese and overweight subjects who volunteered to participate in the study after extensive publicity provided through local newspapers, email communications and leaflet distributions in the southern district of Karnataka, were screened. The subjects who expressed interest to take part in the study underwent a medical examination with a detailed case history using a structured format after the basic screening. Subjects who were diagnosed with a BMI ≥25 kg/m2 as per the criteria of World Health Organization (WHO), aged between 18 and 40 years were chosen for the study. The subjects gave their written informed consent. Fasting naïve (The subjects who have not undergone naturopathic fasting earlier) for at least past 6 months and subjects who were not on any hormonal medications for the past 2 months were included. Individuals with morbid obesity and associated comorbid conditions such as drug-induced obesity (e. g. corticosteroid) or endocrine disorders such as hypothyroidism and polycystic ovarian syndrome and other comorbid medical conditions such as uncontrolled hypertension, hypercholesterolemia, type I and II diabetes mellitus, substance use disorders, females during menstruation, lactation and pregnancy, were excluded from the study. The subject's privacy was maintained throughout the study.
Design of the study
This study is a single-centered, single-blinded randomized controlled trial (RCT). 135 subjects were screened and after applying inclusion as well as exclusion criteria 88 were recruited for the study. The subjects were recruited after the approval from the Institutional Human Ethical Committee (Approval Number: EC-153). Subjects were randomized into fasting therapy group and naturopathic low-calorie diet group after receiving an informed consent. Randomization was done using a computer-generated randomization table. The randomization was maintained by a Naturopathy and Yoga Medical professional, who was not involved in the subject's recruitment or data collection. CONSORT 2010 statement has been followed to report the RCT. The design of the study is delineated in [Figure 1]. The rater and biochemist were blinded to the group status. The sample size was calculated using G* power software, accounting for a larger effect size 0.8 and significance level of 0.05. With a confidence of 95% and attrition rate of 5%, we got sample size n = 42 in each group.
Fasting intervention
Naturopathic fasting therapy was given to the subjects admitted to the Yoga and Nature Cure Hospital. Subjects were kept away from their daily routines so that nothing could interfere with their thoughts and emotions. They had to maintain complete physical and mental rest during the study period with minimal activity. Throughout the intervention period, subjects were under the supervision of a trained Naturopathy and Yoga Physician for 10 days. During juice fasting, the subjects were asked to remain hydrated with approximately 3 liters of water per day.
No other supplementary diet was given to the subjects. They were taught yogic relaxation techniques such as deep relaxation techniques with minimal physical activity such as walking. Naturopathic treatments were administered to manage problems such as headache, dizziness, vomiting, diarrhea etc., during the course of the fasting therapy. Subjects were advised to take enema as a colon cleansing procedure every day during the fasting period. Daily percentages of different macronutrients with dietary fibre given were as follows: Naturopathic diet/day (carbohydrates 56.72%, protein 11.47%, fat 7.47%, fibre 24.34%), Raw diet/day (carbohydrates 48.40%, protein 11.13%, fat 9.90%, fibre 30.57%), Lemon Juice with Honey (LHJ)/day (carbohydrates 92.93%, protein 2.02%, fat 0%, fiber 5.05%), and Musambi Juice (MJ)/day (carbohydrates 83.41%, protein 7.17%, fat 2.69%, fiber 6.73%). Fasting therapy from 3rd day to 7th day was done with LHJ. LHJ (72Kcal) was taken 4 times a day. Therefore, the total calorie intake was 288 Kcal/day. Similarly on the 8th day, fasting was done with MJ (200Kcal) which was taken 4 times a day. Therefore, total calorie intake was 800 Kcal/day. Other details of their daily food with their calorific values are listed in the [Table 1] and [Table 2].
Table 1: Detailed naturopathic based food composition of fasting group (for 2nd, 9th and 10th day)
Table 2: Detailed food composition of low-calorie diet group and first day of fasting groupLow-calorie diet intervention group: The control group underwent a naturopathic low-calorie diet (1234 Kcal/day) for 10 days which consisted of unseasoned boiled vegetables, chapati, daliya, vegetable/fruit salads and sprouts. They were also involved in practicing deep relaxation techniques with minimal physical activity. After the intervention period, fasting was administered to subjects in the low-calorie diet group who desired to undergo fasting therapy. Details of the composition of the food of the low-calorie diet intervention group are provided in [Table 2]. There is a difference between therapeutic short-fasting and therapeutic low calorie diet advised as per the principles of naturopathy.
Outcome measures
All the subjects in both fasting therapy and Naturopathic low-calorie diet groups were assessed by a Naturopathy and Yoga Physician with the following parameters at the baseline and after 10 days. The outcome assessment was conducted by a physician (anthropometric measurements) and a bio-chemist (serum leptin estimation), who were blind to the group's allocation, and not involved in the recruitment of subjects in this study.
Anthropometric variables
Body weight was measured with light clothing and without shoes using a digital weighing machine (Essae, Eeroka limited) and height was measured using a calibrated stadiometer. BMI was measured using the equation BMI = weight (kg)/height2 (m2). Waist circumference was measured midway between the inferior costal margin and the iliac crest using a Gulick Anthropometric tape, U. S. A. The circumference of the hip was measured around the pelvis at the point of maximal protrusion of the buttocks. Lastly, the waist to hip ratio (WHR) was measured to assess the body fat distribution.
Assessment of serum leptin levels
Venous blood (5 ml) was drawn into a plain container from the fasting and low-calorie diet group subjects in the morning between 8.00 am and 9.30 am. After clotting, the serum was separated using a centrifuge for 30 minutes. Then, the serum samples were stored at-40 degree centigrade. The analysis was done by a biochemist within a period of 15 days after collecting the samples in a National Accredited Laboratory (AJ Metropolis, Mangalore). Enzyme-linked immunosorbent assay (ELISA) method was used to access the serum leptin levels (Diagnostics Biochem, Canada).
Data analysis
SPSS version 21 was used to do the final statistical analysis. The distribution of the data was checked using Kolmogorov–Smirnov test. This test indicated that the data was not normally distributed; therefore non-parametric tests were used. Continuous variables were assessed for the baseline differences between the groups using Mann-Whitney U test and Fisher's Exact test was used for the categorical variables. Wilcoxon signed rank test was done to compare pre and post scores within the groups. Group comparisons (change in the pre-post score) was done using Mann-Whitney U test. Spearman's correlation coefficient was used to assess the association of change between two continuous variables. Per protocol analysis was done in this study. Statistical significance was set at a P value less than 0.05.
ResultsOut of a total of 135 obese and overweight persons screened, 115 subjects gave consent to take part in the study. However, 88 subjects were eligible based on the inclusion and exclusion criteria. Finally, 88 subjects were randomized into either fasting therapy (n = 44) or low-calorie diet intervention (n = 44) group. Eventually, 42 subjects in the study group and 42 subjects in the low-calorie diet intervention group subjects were eligible for the final analysis for which both baseline and 10th day follow-up assessments were available. Details are delineated in the CONSORT Flow Chart [Figure 1].
[Table 3] shows that all the variables were comparable at the baseline in both the groups with respect to socio demographics, illness characteristics, anthropometrics and leptin parameters [Table 3].
Table 3: Sociodemographic, anthropometric, leptin and illness characteristics at the baseline[Table 4] presents within group difference using Wilcoxon signed-rank test, which indicates both the groups did better in all the parameters. However, greater changes were observed in the fasting group in comparison to the low-calorie diet group.
In addition, [Table 4] presents changes observed with Mann-Whitney U test (pre-post change scores). Results suggest that there was a significant group difference with respect to changes in BMI, weight, WC, HC, WHR (P < 0.05), except for serum leptin (P > 0.05).
These results indicate greater reductions in weight with short-term fasting therapy. Furthermore, mean percentage reduction of leptin levels in fasting group (47.1%) and low-calorie diet group (24.12%), suggests a significant reduction in leptin levels occurring in the fasting group in comparison to naturopathic low-calorie diet group.
DiscussionThe primary goal of obesity management in primary health care is to lose 5-15% of the initial body weight.[21] Our results suggest that significant changes in BMI, weight, HC, WC and WHR were observed in both the groups (fasting and low-calorie diet). However, final between group differences is not statistically significant for serum leptin. Furthermore, the magnitude of significant changes was observed more within the fasting group in comparison to the low-calorie diet group.
The within-group comparison showed that both the groups did better in all the parameters and greater changes were observed in the fasting group in comparison to low-calorie diet group. A significant positive correlation was observed between weight and BMI in both the groups.
Fasting and weight reduction
Weight reduction of 5.24% obtained in this study is consistent with the previous studies. Fasting for 14 days with fermented medicinal herbs and carbohydrates (400-600 kcal/day) resulted in mean 5.16 weight loss among 26 subjects.[22] Another study reported that the traditional dietary approach to weight reduction brings about greater weight loss with 600 kcal/day diet in comparison with a low-calorie diet (1200 kcal/day).[23]
Low-calorie diet and weight reduction
Weight reduction of 2.57% obtained in this study is consistent with the previous studies. Among post bariatric surgery patients, 700-1050 kcal diet intake led to 5% further weight loss on low-carbohydrate diet.[24] A recent meta-analysis reported more weight loss with low carbohydrate diet (mean 8.73 kg) at 6 months and 7.25 kg at 12 months, whereas the reduction in weight loss in low-fat diet was 7.99kgs at 6 months and 7.27kgs at a 12-month follow-up. Weight reduction across different dietary studies was minimal. Atkins diet resulted in 1.71 kg reduction in weight than Zone diet at a 6-month follow-up. Since differences in weight reduction was minimal across different types of diet, it was recommended to use any kind of diet for weight reduction.[25] These results suggest the magnitude of weight reduction is more in the present study based on Naturopathic fasting therapy and naturopathic low-calorie diet. Although weight reduction was observed after the study period with different types of branded diets, sustained weight reduction was not evident on a long term basis with these diet patterns.[26]
Leptin and weight reduction
Leptin is present in a greater concentration in obese persons in comparison to lean persons.[27] In our study, reduction of leptin levels was observed in both the fasting group and naturopathic low-calorie diet group, but no difference was observed between the groups. Percentage of reduction of leptin levels in fasting (47%) and low-calorie diet (24.12%) were consistent with the previous studies. One study showed a significant change in serum leptin levels with short-term fasting for 52 hours. In this study, leptin mean reduction was from 31 to 12 ng/ml (61.3%) in obese subjects and from 11 to 4 ng/ml (63.64%) in normal weight subjects. The results suggest a reduction in leptin levels were related to regulatory factors other than changes in body fat mass.[28] Also, another study showed 20% reduction in serum leptin levels after a 24 hour fasting in obese subjects along with a reduction in BMI.[29] Interestingly, leptin concentration is directly proportional to body fat mass suggesting leptin resistance is more important than leptin deficiency in obese persons.[5]
Possible mechanisms behind these changes in weight loss and other anthropometric measurements in both fasting therapy and naturopathic low-calorie diet are listed below. Lemon juice used in fasting and naturopathic diet group is enriched with vitamin C. Lemon juice with honey has showed to be beneficial by reducing BMI and weight in healthy subjects.[30] Interestingly, vitamin C levels are inversely related to the body mass indicating obese individuals oxidize 30% more fat during a moderate exercise regimen than individuals with vitamin C deficiency.[31] Increased intake of whole grains, fruits, and vegetables are beneficial in obesity because whole grains and vegetables have low glycaemic index and fruits contain more fibre, anti-oxidant, phytochemicals and minerals.[32] The presence of undigested carbohydrates in whole grains gives bulk to the fecal matter and reduces the intestinal transit time, thereby reducing the risk of weight gain.[33] Furthermore, consumption of a minimum 48 g of whole grains/day is beneficial in weight maintenance and vascular disease prevention.[34],[35] Short term fasting for 10 days is more beneficial and does not result in any adverse effects because fasting process does not affect the vital organs.[36] Also, there is an increased beta-oxidation observed during fasting.[37] Very low-calorie diet (450 to 800 Kcal/day) has many advantages such as rapid weight loss, which acts as a motivating factor for obese persons and also the mild ketosis formation suppresses hunger and slows down protein loss.[38] Also, VLCD should be used for less than 16 weeks because of the adverse effects related to this.[39] Breaking the fast is considered equally important in Naturopathic philosophy and practice.[14] It was done with Musambi (sweet lime) juice consumption for a day as it is thicker, having more fibercontent so that the subject's system could be prepared for the subsequent return to raw diet followed by a boiled diet. Two subjects from fasting therapy group dropped out from the study due to acute symptoms such as headache, nausea, and fever. Such acute symptoms are considered as the body's effort to eliminate the toxins from the system and are encouraged in Naturopathy. However, discomfort due to such crises could be managed well using simple naturopathic treatments such as enema, ice water sipping, ice bag on the abdomen, hip bath, hot foot bath and by drinking copious amounts of water.[14] Two other subjects in fasting therapy were managed well with similar mild complaints. The subjects in both the groups were advised to do regular walking during this period to prevent muscle loss.[38]
Merits, limitations and future directions of the study
This is the first single-blinded, prospective RCT study, which looked at the short-term effects of naturopathic based fasting therapy and low-calorie diet in obese or overweight persons. Follow up was not done after 10 days of intervention and absence of an active control arm were the main limitations of the study. Also, we have kept higher effect size instead of moderate effect size in the absence of relevant literature. Sample size calculation error could be another weakness of the study. Although VLCD is beneficial in the short-term reduction of weight, the risk of weight gain is more in this due to binge eating.[15],[39] In addition, body loses large volume of water and also muscle mass for some extent. Once the obese or overweight persons are back on a regular diet, the percentage of weight loss is smaller. Therefore, future directions should focus on long-term sustained adherence of these different types of diets on weight loss. Furthermore, studies should focus on comparing these two groups with routine vegetarian and non-vegetarian diets.
ConclusionsThe findings support that both the naturopathic based fasting therapy and the low-calorie diet are beneficial in reducing leptin levels and anthropometric parameters among obese or overweight persons. However, long-term dose and effect relationships with respect to weight loss adherence and prevention of overweight or obesity with these interventions should be tested with future studies.
Clinical trial registration
The registration number for this clinical trial is CTRI/2018/02/011978. Registered inthe Clinical Trials Registry-India (CTRI). We have intended to publish other variables data from this study such as lipid profile and heart rate variability in a separate original article as per CTRI.
Acknowledgement
The authors would like to thank Ministry of AYUSH, Government of India for funding the research project.
Financial support and sponsorship
Funding from the Ministry of AYUSH through Central Council for Research in Yoga and Naturopathy (CCRYN), Government of India, as part of a grant (Z 28015/74/2013-HPC (EMR) –AYUSH-B).
Conflicts of interest
There are no conflicts of interest.
References
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