Diet versus exercise in “the biggest loser” weight loss competition

Abstract

The Biggest Loser television show is watched by millions of people worldwide. Obesity experts have criticized its portrayal of an unrealistic intervention that raises false expectations for weight loss. Here, I quantify the diet and exercise intervention using a validated computational model of metabolism to integrate data on energy expenditure, body weight and body fat collected during The Biggest Loser competition.Participant age, body mass index, weight, and percent body fat at baseline were 33 ± 11 y, 48.7 ± 10.1 kg/m2, 144.9 ± 39.4 kg, and 49 ± 6 % (mean ± SD), respectively. During the first phase of the competition when the contestants were isolated in a boot camp environment, the average rate of weight loss was 0.4 ± 0.1 kg/d which decreased to 0.19 ± 0.1 kg/d after returning home for the final phase. The total weight loss was 58.2 ± 26 kg with 81.6 ± 8.4 % coming from body fat. The computer simulations closely matched the data and calculated that average energy intake during the first phase was 1300 kcal/d while participating in 3.1 h/d of vigorous exercise. After returning home, energy intake increased to 1900 kcal/d and vigorous exercise decreased to 1.1 h/d. Simulation of diet alone resulted in 34 kg of weight loss with 65% coming from body fat, whereas exercise alone resulted in a loss of 27 kg with 102% from fat. Simulated weight loss maintenance could be achieved with a modest 20 min/d of vigorous exercise and a 3000 kcal/d diet.

Losing Weight on Reality TV: A Content Analysis of the Weight Loss Behaviors and Practices Portrayed onThe Biggest Loser

“…Furthermore, Thomas and colleagues (2007) concluded that few sustainable real life weight loss strategies were presented. A recent study of TBL by Hall (2013) corroborates the assertion made by Thomas and colleagues. Through mathematical modeling, Hall estimated that contestants TBL engaged in 3.1 hours of daily vigorous physical activity while on the ranch, and that their activity declined to 1.1 hours of daily vigorous physical activity when they returned home; caloric intake increased from an average of 1,300 kcals=day to approximately 1,900 kcals=day (Hall, 2013).…”

Fat-free mass is not lower 24 months postbariatric surgery than nonoperated matched controls

“…There is now clear documentation that intense physical activity can reduce FFM loss that results from significant weight change [25]. However, we made no effort to attempt to assess the exercise level of the patients and controls on the basis of physical activity evaluations reported from the Longitudinal Assessment of Bariatric Surgery, which report, even after surgery with its resultant weight loss, that few patients begin or sustain efforts to increase activity, and some even reduce their activity level [26], Another group confirmed that after weight loss surgery their sample of patients was still spending >70% of their time in sedentary behaviors [27].…”

Validation of an inexpensive and accurate mathematical method to measure long-term changes in free-living energy intake

“…Based on the energy balance principle, mathematical models of human metabolism and body composition dynamics have been suggested as an inexpensive and simple alternative to the DLW/DXA 1 approach, but such methods have been validated only in small numbers of subjects over relatively brief time periods (11)(12)(13)(14)(15)(16)(17)(18). Here, we validated the EI changes calculated by a popular mathematical model of human body weight dynamics from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) (14,16) by using repeated DLW/DXA measurements collected over 2 y of caloric restriction in 140 free-living subjects participating in the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) study (19)(20)(21).…”