|Feasting and a wasp waist? Does bring the two together?|
- rising before sunrise and having breakfast will minimize the fasting window - While most people I know personally don't do this, there are families, where everyone gets up before the sun rises to have breakfast. With the huge dinner before bed and a (usually smaller) breakfast right after you stand up in the early AM, the fasting window which would otherwise be up to 18h wide can become pretty narrow.
- not drinking during the fast - It is religious practice, so I am not in the position to criticize it, but for anyone fasting for health purposes not drinking anything during the fasting hours is absolutely not advisable.
- food / diet quality - The average Westerner will probably assume that the food quality sucks during Ramadan, after all the family-get-togethers are not exactly occasions to eat chicken, rice and broccoli, but compared to the regular diet of the inhabitants of the Western obesity belt the self-prepared meals from real food ingredients will probably still entail an improvement in overall diet quality for many people who are fasting for religious reasons.
31" waist as a starting value? Obviously not a US study*
Ramadan fasting increases fatty acid oxidation: In 1995 Jalila El Ati and her colleagues were able to show that the respiratory quotient, i.e. the ratio of carbs / fats that are being burned as fuel decreases by ~10% in healthy 25-39 year old women (El Ati. 1995).The study was conducted at the research lab of Department of Physiology Bhaskar Medical College during the month of Ramadan in the year 2011 (Aug - Sept). The subjects were 50 young adults in the age group 18-24yrs - with 6 dropouts (personal reasons) that leaves us with data on the changes in body composition, blood pressure, and heart rate from 44 subjects, whose baseline BMI (24kg/m²) was very different from that of the "average" American and whose 31.5" waist is a clear indicator that they were in pretty good shape (compared to those who are currently totally digging alternate day fasting after they have failed with the South Beach, the Weight Watchers and the rest of the "I am a stupid lazy ass and don't want to make the appropriate lifestyle changes" diets in the past.
* Health alarm: Did you know that the average US teenager had a 34" waist, in 2004? That was already 2" more than 5 years before (Li. 2006; data based on NHANES 2004). If we extrapolate a yearly increase of 0.25" this means we should have arrived at 35.25" today.You will often hear the proponents of the the idea that some people are simply "naturally lean" state that this is usually a result of the fact that they are eating "frequent small meals" to satiety. So, based on that argumentation you would actually expect that the subjects in the study at hand, who would probably qualify as "naturally lean", may have jeopardized this "natural leanness" by robbing themselves of the opportunity to keep "grazing".
|Figure 1: BMI, waist and hip circumference and body fat % before and after 28 days Ramadan fasting (Shruti. 2013)|
If you take into account that the scientists measured only subcutaneous fat (this is a necessary result of using the skinfold method), which is usually comparably slow to respond, it certainly argues for the cosmetic advantage of timed feasting over uncontrolled all-day snacking - whether the same would yet be true if we standardized the caloric and macronutrient intake is questionable (see my comment on the 2-day a week fast in the box below, as well).
Why do the fast 2x per week diets work? It's easy the main working principle is a reduction in calorie intake. If you assume you have a 2,400kcal intake and cut back to 800kcal (some prescribe 500kcal) on 2 days that's a 66% (80%) reduction in energy intake. Interestingly, though the compensation effect is much less pronounced than you would expect and occurs usually only on the days after the fast. So, 10% more on the days after the fasting days leaves us with a caloric deficit that will still amount to 2.720kcal (3320kcal for the 500kcal variety) or 10% (20%) per day.Impressive it is, but in the end it's still basic mathematics: As impressive as it may be, the underlying reason - and this is something all previous Ramadan studies appear to support a simple reduction in energy intake that is, at least in some cases, supported by improvements in diet quality, reductions in carbohydrate and increases in protein intake that are brought about by the elaborate cooking, the absence of snacks and sugar sweetened beverages and the mere fact that you simply cannot stomach the same amount of food you would usually consume in three main meals and two snacks within one or two meals... no matter how huge those meals may be.
Does that exclude that "having AMPK come to its right", sirtuins, increased fatty acid oxidation and the whole fastin' hoopla may figure here, as well? No it does not, but even the significant reduction in systolic and diastolic blood pressure in the study at hand, as well as the improvements in glycemia and lipid metabolism in previous Ramadan studies are, when all is said and done, eventually brought about by the downstream effects of a reduced calorie intake. And this, is by the way also true for the "eat whatever you want all week long and cut back to 800kcal (or 500kcal) mainly from protein on two out of seven days" diets as well (see infobox to the right for an example calculation).
- el Ati J, Beji C, Danguir J. Increased fat oxidation during Ramadan fasting in healthy women: an adaptative mechanism for body-weight maintenance. Am J Clin Nutr. 1995 Aug;62(2):302-7.
- Li C, Ford ES, Mokdad AH, Cook S. Recent trends in waist circumference and waist-height ratio among US children and adolescents. Pediatrics. 2006 Nov;118(5):e1390-8.
- Shruthi B, Hassan A, Reddy BV. The Effect of Ramadan Fasting on the Body Composition, Blood Pressure, Heart Rate of Healthy Young Adults. International Journal of Recent Trends in Science And Technology, ISSN 2277-2812 E-ISSN 2249-8109, Volume 8, Issue 1, 2013 pp 31-35.