by Ashley Jordan Ferira, PhD, RDN
With over 70% of US adults overweight or obese,1 weight loss methods that are effective and sustainable over the long-term are critically needed. A National Institutes of Health (NIH) study led by Kevin D. Hall, PhD investigated how physical activity (PA) and energy intake (EI) impacted long-term weight loss in participants from “The Biggest Loser” TV competition.2
“The Biggest Loser” is a televised weight loss competition involving an intensive diet and exercise program (30 weeks) for participants with class III obesity (BMI ≥ 40). In the NIH study, body composition, resting energy expenditure, EI, and PA were measured in 14 participants at baseline, week 6, week 30, and 6 years following the competition. After losing an average of 132 pounds during the TV competition, many participants experienced weight gain following the program. The median weight loss 6 years following the competition was 13%, but significant weight loss differences were observed based on PA levels. Six years after the competition:2
- Weight maintainers (7 participants): increased their PA by 160% ± 23% and experienced an average weight loss of 24.9%
- Weight regainers (7 participants): increased their PA by 34% ± 25% and experienced an average weight loss of 1.1% (i.e. heavier than their pre-competition weight)
- An increase of ~80 minutes/day of moderate physical activity or 35 minutes/day of vigorous activity was necessary to maintain lost weight
Energy intake reductions were similar between weight loss maintainers (-8.7%) vs. regainers (-7.4%). Weight regain was strongly associated with absolute changes in PA, but not with changes in EI. This prospective analysis of “The Biggest Loser” participant cohort underscores the importance of moderate-to-vigorous daily physical activity in long-term weight loss maintenance.
Study strengths include use of gold standard methodologies: dual-energy X-ray absorptiometry for body composition, indirect calorimetry for resting energy expenditure, and doubly labeled water technique for EI and PA. These methods significantly improve upon previous, related studies, which utilized self-reported PA. Limitations of the current study include a small sample size and lack of data between the end of the competition and 6-year follow-up.
Why is this Clinically Relevant?
- Partial or complete weight regain is common following lifestyle interventions for weight loss
- While caloric reduction is important for weight loss and maintenance, persistent increases in physical activity may be more strongly associated with long-term weight loss success
- Practitioners should encourage and help implement regular physical activity regimen in their patients at every patient visit and partner with an exercise specialist when possible
- National Center for Health Statistics. Health, United States, 2016: With Chartbook on Long-term Trends in Health. Table 53. Hyattsville, MD. 2017. https://www.cdc.gov/nchs/data/hus/hus16.pdf#053. Accessed February 9, 2018.
- Kerns JC, Guo J, Fothergill E, et al. Increased physical activity associated with less weight regain six years after “The Biggest Loser” competition. Obesity. 2017;25(11):1838-1843.