|This is not the kind of refeed I would suggest - irrespective of how effective refeeds are using all of them to pig out to the extremes will be counter-productive.|
Yes while the efficacy of this practice has been demonstrated before (more), previous studies did not have an appropriate control group that would allow us to say for sure whether dieting continuously wouldn't have yielded the same results.
To change that Radhika V. Seimon and colleagues from the Sydney Medical School conducted a preliminary, but highly interesting rodent trial. In said study, male C57/Bl6 mice that had been rendered obese by an ad libitum diet high in fat and sugar for 22 weeks were then fed one of two energy-restricted normal chow diets for a 12-week weight loss phase.
- The continuous diet (CD) provided 82% of the energy intake of age-matched ad libitum chow-fed controls.
- The intermittent diet (ID) provided cycles of 82% of control intake for 5–6 consecutive days, and ad libitum intake for 1–3 days.
|Figure 1: Study flow chart. CAC, continuous ad libitum chow; CAF, continuous ad libitum high fat; |
CD, continuous diet; ID, intermittent diet (Seimon. 2016).
Yes, this is just a rodent study, but... it is better than no study and the results are at least partly in line with the previously cited study in obese women (read more) who lost 8kg of pure fat in 42 days by calorie shifing - 2.6x more than the calories in vs. out prediction would suggest.As you can see in Figure 2, both the ID and CD group lost a significant amount of weight during the weight loss phase. In that, it is quite remarkably, though, that (a) the intermittent diet (ID) phase created a continuous up and down, and that (b) the continuous dieting group lost almost all the weight in the first fifth or fourth of the dieting phase, while the intermittent diet group lost its weight continuously (albeit with mini-rebounds / probably water / during refeeds).
|Figure 2: Body weight development (g) over the 22+12+3 week weight gain, loss and regain phase (Seimon. 2016).|
"During the weight loss phase, there was a significant, 2.3-fold greater weight loss efficiency (total weight loss total energy deficit) for mice on the intermittent diet compared to those on the continuous diet. This is because whereas both groups of energy-restricted mice exhibited similar total weight loss (Fig 2), the total energy deficit of mice on the inter mittent diet during the 12-week weight loss phase (304.5±47.7 kJ) was less than half that of mice on the continuous diet (646.9±16.8 kJ). This means that for every kJ of deficit in energy intake relative to the energy intake of age-matched control mice, mice on the intermittent diet lost 2.3 times as much weight as mice on the continuous diet (Seimon. 2016)."No such significant difference was observed for the weight regain and the body composition, though. While the mice in the CAF group were obviously the fattest and kept gaining weight continously, the the fat mass of the mice in the intermittent and continuous diet groups did not differ significantly after dieting and were in fact similar to that of the lean rodents in the control (CAC) group.
That's also because the differences in the intermittent and continuous diet groups' glucose and insulin levels may not be significant, but they exist with the ID group suffering a sign. less pronounced reduction in insulin (way below control) during dieting and had 15.7% lower insulin levels after the weight regain phase - all that at stable (=group-equivalent) serum glucose levels.
- Seimon, Radhika V., et al. "Intermittent Moderate Energy Restriction Improves Weight Loss Efficiency in Diet-Induced Obese Mice." PloS one 11.1 (2016).