"...people do not regain weight because they lack willpower."

For Better Health, Trim Weight-Loss Goals

The good news is that, thanks to groundbreaking obesity research conducted during the last few decades, we now know why it is so hard to sustain weight loss. Since the 1980s, when most scientists thought fat cells were inert storage vessels, we have discovered that they are in fact engines in a vast and complicated network,which interacts with the brain to control hunger, metabolic rates, and other key functions.

Unfortunately, these insights into how our bodies work have not led to reliable interventions to control them. This suggests two lessons. First, people do not regain weight because they lack willpower. Instead, their best efforts are countered by powerful biological responses that fight them at every turn. The second lesson comes from my University of Michigan colleague, Dr. Charles Burant: “Don’t get heavy in the first place.”