Yo-Yo Dieting is the consistent decreasing (when you initially start a diet) and increasing (when you end the diet) of your body weight over time.   The more you try diet through this cycle, the greater the probability you’ll continue to gain weight in the long term.   It’s also a primary reason why 95% of all diets fail.  In his book, “Fat Loss Forever”, Dr. Layne Norton describes our body’s “self defense system” that is activated whenever we diet.   This self defense system is an evolutionary human trait that was originally adapted to prevent dying from starvation.  The degree to which our body’s self-defense system works is dependent upon how much we’re restricting calories and how long/often we’ve been dieting.   The greater our calorie deficit, longer or more frequently we’ve been dieting, the more difficult it will be for us to be successful in weight loss.  Dr. Norton lays out the self defense system in 3 parts:

  • Defend – Metabolic adaptation, in which our metabolism slows down to defend against starvation.  Our metabolism becomes slower than what it should be based on predictive equations.  This prevents further weight loss and is the cause of why we “plateau”.
  • Restore – An increase in hunger and promotion of fat storage while we’re dieting.  This sets the stage for rapid weight gain once we stop dieting.
  • Prevent – The increase in the number of fat cells if we regain weight, post-diet, too quickly.   This prevents us from future weight loss, or at least makes it much more difficult.

Our self-defense system came in handy when our ancestors needed to hunt and gather their food.  Without it, they would have faced the possibility of starvation.  In modern times, especially in developed nations, food scarcity is not an issue.   In fact, we have more food options than we know what to do with.  Combined that, with a sedentary lifestyle, and it’s easy to see why so many of us are looking to lose weight.  Unfortunately, that same self defense system that protected our ancestors from starvation is the same mechanism that prevents us from sustainably losing weight, especially with the restrictive approach of many popular diets.   With these odds stacked against us, it’s imperative to take a weight loss approach with sustainability as a top priority.