Exercise, metabolism, and weight: New research from The Biggest Loser - Harvard Health

🌈 Abstract

The article discusses new research findings from studies of contestants on the reality TV show "The Biggest Loser" regarding the relationship between exercise, metabolism, and weight loss. It explores how intense physical activity and dramatic calorie restriction can lead to a significant slowdown in metabolism, which can make it challenging to maintain substantial weight loss over the long term.

🙋 Q&A

[01] Staying Healthy: Exercise, metabolism, and weight: New research from The Biggest Loser

1. What were the key findings from previous studies on The Biggest Loser contestants?

• Previous studies showed that metabolism slows drastically following significant weight loss, and regaining the lost weight does not restore metabolism back to its pre-weight loss levels
• This means people who have lost large amounts of weight must adhere to an extremely low-calorie intake to maintain that weight loss

2. What is the "constrained model of human energy expenditure" proposed by Dr. Kevin Hall?

• Dr. Hall theorizes that because the contestants engaged in large, sustained periods of intense physical activity, their metabolisms slowed substantially in order to reduce their metabolic rates and maintain energy balance
• This metabolic adaptation is a response to the dramatic increase in physical activity, rather than just the calorie restriction

3. What did the new study find about the relationship between metabolism adaptation and weight regain?

• The degree of metabolism reduction was not related to contestants' subsequent weight regain
• In fact, the contestants that maintained the greatest weight loss six years after the competition actually had the greatest amount of metabolism adaptation

4. What is the key takeaway about weight loss maintenance from these studies?

• The compensatory mechanisms do not completely counteract lifestyle changes, so it is possible to keep off substantial amounts of weight through sustained increases in physical activity
• However, additional studies are still needed to fully understand the relationship between body composition, physical activity, energy regulation, and weight maintenance

[02] What have we learned about weight loss from studying The Biggest Loser contestants?

1. What are the key lessons learned from studying The Biggest Loser contestants?

• Short-term reductions in resting metabolic rate are related to the extreme calorie restriction during active weight loss
• The larger, persistent metabolic adaptation is related to substantial sustained increases in physical activity
• Physical activity is a key component of successful long-term weight maintenance, as demonstrated by the National Weight Control Registry

2. What is still unknown about the relationship between physical activity and weight maintenance?

• How sustained increases in physical activity lead to improved maintenance of lost weight, despite the compensatory long-term reduction in resting metabolic rate
• Dr. Hall theorizes this could potentially be due to the effect of physical activity on lowering appetite, but more research is needed

3. What are the general recommendations for maintaining a healthy body weight?

• Eat healthy whole foods in moderation
• Avoid processed foods
• Engage in regular physical activity