Calorie shifting is an idea espoused in several books and diet programs, particularly the Idiot Proof Diet. This diet in particular suggests that people tend to be able to lose weight on other diets, by reducing carbohydrates or calorie intake, but then quickly gain the weight back because the metabolism adjusts to a lower calorie intake, and slows down accordingly. The Idiot Proof Diet, and other diets like the zig-zag diet propose that you have to keep the metabolism “guessing” so it doesn’t prevent weight reduction by slowing down to accommodate a reduced calorie eating style.

The basic premise of calorie shifting includes the following concepts:

• Instead of eating the same calories and types of foods each day, people evaluate total calorie needed for a week.
• Rather than eating the same amount of calories each day to reach this total, people vary their calorie consumption amounts each day while still remaining within the total weekly calorie allotment.
• Since the body doesn’t know what to expect, the metabolism can’t adjust or slow down because calorie intake on a daily basis will be variable.
• Further the metabolism can’t adjust to certain foods, since foods eaten will vary in nature.

Do you really need a book to tell you how to do this? Most people who have practiced calorie shifting suggest all you really need to try this diet is a good calorie counter so you can estimate your total calorie intake for each day. Further, you do need to plan ahead so that every day you can eat a different amount of calories. If your total calorie allotment for the week works out to 1200 calories a day, some days you’d consume less than 1200 calories and other days you’d consume more.

There are some problems with diets that have you consuming less than 1200 calories a day. When you are calorie shifting down into the 1000s or 900s, some people begin to feel faint, dizzy or nauseous. At least from an anecdotal standpoint, calorie shifting, especially on very low calorie days, may be problematic. It’s recommended by many nutritionists that you don’t consume less than 1200 calories a day, especially not on a regular basis, even if you are calorie shifting to higher amounts on other days.

The method of changing calories from day to day certainly existed before diets like the Idiot Proof Diet. Weight Watchers® has had varied systems for years where you can change daily point or calorie intake. While some people give anecdotal evidence that these programs are very effective, there isn’t significant scientific evidence to suggest that these programs actually change your metabolic rate.

As with any diet or exercise program, you should discuss your plan to use calorie shifting with your physician. It may be that this concept works well for you. On the other hand, some doctors still recommend that following healthy eating plans daily and getting adequate exercise are more likely to help take weight off gradually, which is more likely to be permanent.