Why fad diets work. And then don’t.

dietcollageTrue Fact: Fad diets drive nutrition experts crazy.

Why?  Because despite the fact that they never really work, they refuse to go away.  There’s always a new fad diet and millions of dieters jumping on the bandwagon.  After all the hysteria dies down and the weight has been regained, people are easy prey for the next fad.  Why do dieters keep falling for this merry-go-round of weight loss and gain?

Here are the 2 main reasons fad diets aren’t going away:

  1. They always seem to work at first.  Sometimes with dramatic results.  Losing 10 or more lbs in one week is likely to make anyone a true believer.  When you restrict calorie intake for several days, your metabolism first burns off stored carbohydrates, in the form of glycogen, to make up for the energy deficit.  Glycogen is stored with water, so as glycogen is burned, that water is flushed out.  Result: quick and dramatic weight loss.  It looks good on the scale, and might provide a psychological lift that motivates the dieter, but it’s mostly water.   Once the glycogen is gone, assuming you stick to your low calorie fad diet plan, you start burning fat.  Weight loss slows down.
  2. They create strict, easy-to-understand food boundaries.  Dieters like Good and Bad food lists.  They seem to have a very hard time with open-ended plans that just say “eat smaller portions”.  When potato chips, ice cream, french fries and cookies are still theoretically permitted, then it’s hard to control portions.  Plenty of people like fad diets that forbid certain foods or entire food groups.  That makes it easy to plan.  If lots of foods are forbidden, you simply don’t even think about them.  Sure, it’s an entirely arbitrary and artificial boundary system, but for many dieters, it’s what works.  The food choices are limited, making it easier to choose foods.

But if fad diets really worked, we wouldn’t have any obesity epidemic.  So clearly despite the food boundaries and psychological motivation of early success, something goes wrong.

 Why fad diets never work longterm:

  1. Weight loss slows down.  It’s inevitable.  Once the glycogen is gone, loss of fat is a much slower process, complicated by metabolic changes that accompany weight loss and slow it down even more.  The more you lose, the slower you lose.    This is extremely discouraging.  After the initial euphoria of quick weight loss, the diet just drags on.  The dieter becomes discouraged and is more easily tempted to cheat or give up.
  2. Reality intrudes on the food boundaries.  Holidays, vacations, celebrations and just plain life relentlessly chip away at the food boundaries of any fad diet.  A tempting restaurant meal, a piece of cake, a pastry at the office, a late-night bowl of ice cream — as these little transgressions become more frequent, you gradually lose your motivation to stick to the fad diet restrictions.   Made worse by the fact that…..
  3. The diet taught you nothing about normal eating.  Instead of having a small piece of that birthday cake, or avoiding the all-you-can-eat lunch special, you go overboard when you cheat.  The fad diet was based on a falsely restrictive food selection, not the selection you encounter in the real world.  As your motivation fades, your default is the way you used to eat.  The way that made you obese in the first place.  You didn’t learn anything about eating a balance of foods that would help you remain at a normal weight in a world full of food choices.

So where’s the fad diet that teaches you to eat normal food in the real world and maintain a healthy weight?  There isn’t one.  By definition, a fad diet will not do that.  Fads are about short term fixes for a life long problem.  Think about it this way: if a fad diet gave you the long-term fix, you’d never need a new fad diet.  And that’s would not be good for the fad diet business.   The main purpose of fad diets is to make money for the diet book authors and publishers and websites.  Not to help overweight people achieve and maintain a normal weight.

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