The idea of “starvation mode,” where drastically reducing calorie intake supposedly halts weight loss, is a common concern among dieters. This belief suggests that the body, sensing deprivation, slows metabolism to conserve energy, preventing further weight loss. But is this actually true?
The “Minnesota Starvation Experiment,” conducted in 1945, provides valuable insights. Researchers subjected 32 men to a severe 55% caloric deficit for 24 weeks. Contrary to the starvation mode theory, the participants lost significant weight, averaging a 25% reduction in body weight.
While their metabolisms did slow down, this was largely attributable to the loss of body mass itself. A smaller body requires less energy. However, a smaller adaptive metabolic slowdown did occur, primarily due to a decrease in non-exercise activity thermogenesis (NEAT). NEAT encompasses everyday movements like fidgeting and walking.
This reduction in NEAT, while real, wasn’t enough to prevent continued weight loss, even in the face of a dramatic calorie restriction. It’s important to remember that these participants reached extremely low body fat percentages before experiencing this level of metabolic adaptation.
Minnesota Starvation Experiment participant
Beyond metabolic adaptation, other factors can explain weight loss plateaus. People often underestimate their calorie intake, potentially consuming more than they log. Water retention, influenced by factors like stress and menstrual cycles, can also mask fat loss on the scale.
:max_bytes(150000):strip_icc()/how-to-weigh-yourself-accurately-1231063-v2-e1c2a57c718f41b785df7a349899260a.png)
While “starvation mode” isn’t a valid explanation for weight loss stalls, extremely low-calorie diets aren’t recommended. They can lead to greater metabolic adaptation, muscle loss, and post-diet weight regain. A moderate calorie deficit of 15-25% or aiming for a weekly weight loss of 0.5-1% of body weight is generally more sustainable and effective.
:max_bytes(150000):strip_icc()/1046856_color-e70950d716724032a397f36a24845094.png)
So, the myth of “starvation mode” is busted. Weight loss stalls are often due to other factors, and a more moderate approach to dieting is generally more beneficial for long-term success.
