The Biggest Loser Studies were Crap
“Metabolic adaptation at the level of RMR is minor when measurements are taken under weight stability and is not sustained in the long term with weight regain. More importantly, metabolic adaptation does not predict relapse in the long term”
“The aspects discussed previously are of paramount relevance as they are likely to explain the discrepancy in the literature regarding the existence or not of metabolic adaptation. All the studies reporting no metabolic adaptation at the level of RMR are studies where weight-stable, reduced-obesity individuals were compared with never-obese BMI-matched controls (2, 4, 18, 35) or against a regression model (20). In contrast, longitudinal studies tend to find metabolic adaptation (1, 9, 36), likely because measurements are taken under negative EB. For example, in the landmark paper by Leibel and colleagues (1), even though participants were weight stable for 2 wk, they were, most likely, in negative EB as a 800-kcal/d ketogenic diet was used to induce weight loss (as in the present study). Results from the “Biggest Loser” study suffer from the same problem, as participants were clearly in negative EB at the end of the 30-wk competition and, even at 6-y follow up, there was a very large interindividual variation in weight stability, with some participants gaining up to 3 kg and some losing up to 3 kg over the 2 wk preceding RMR measurement .”
“If metabolic adaptation was part of a compensatory response
that tries to bring body weight back to its original state and,
therefore, a driver of weight regain, then it would be expected that
a larger metabolic adaptation was associated with more weight
regain long term. That is not the case, either in the present
analysis or in the available literature (9). In fact, the evidence
suggests metabolic adaptation to be a reflection of the magnitude
of weight loss: the larger the weight loss, the larger the metabolic
adaptation (9, 10, 36). This pattern was observed in the present
analysis among blacks, where a larger metabolic adaptation was
associated with greater weight loss and less weight regain.”
“In line with the evidence previously discussed for RMR,
the existence of metabolic adaptation at the level of nonresting
EE after weight loss (due supposedly to increased exercise
efficiency) is also likely to be modulated by the EB status of the
participants when measurements are taken. As such, no metabolic
adaptation was found in nonresting EE (3, 37–39) following a
10- to 12-kg weight loss in overweight premenopausal women
when measurements were done in controlled conditions of
weight stability. Moreover, to our knowledge, no study has
ever reported increased exercise efficiency with weight loss to
be associated with long-term weight regain. In fact, improved
locomotion economy/efficiency may actually reduce the risk
of weight regain, as several studies have shown that exercise
training–induced increases in exercise economy are associated
with increased ease of locomotion (40–43), which, in turn, is
associated with increased participation in free-living physical
activity and reduced weight regain”
“Therefore, the concept of metabolic adaptation as a major
driver of weight regain should be put to rest”
