Why a weekend of bad eating won’t ruin your weight-loss efforts.

A diligent dieter navigates the busy schedule of a week with planned meals, timing, and structure. They live in a calorie deficit, which provides them weight loss. They eat healthy and do what a sensible diet plan asks: eat a little less, and choose lower-calorie foods. Now, the weekend is coming, friends going out to brunch. Saturday night sports, with all the accoutrements. Sunday is a late-afternoon pizza because no one wants to cook.

Our dieter is ashamed and feels like all of the week’s effort was for naught. This, however, is not true, because of a few different physiological processes our bodies have as an energy-storage mechanism.

How can someone eat well above their caloric needs and not gain weight? This person must be calorically diminished from dieting. This means eating less than daily requirements for multiple days. This is important because our bodies have a fuel tank of stored glycogen (created from digesting food we eat). This storage tank is for exercise and energy on the fly. A person can store up to 2,000 calories depending on their size and muscularity.

A person who is dieting first depletes this storage, not actually losing body fat until it is gone. If we’ve been dieting and exercising for multiple days this would put us into a low stored-glycogen mode. Since this storage is the first thing to go during a diet phase, this will also be the first thing to be re-absorbed when overeating.

This is the most important piece: Depending on how low a state of stored glycogen we’re in, the body will always replenish this first. A person can — theoretically — eat up to 2,000 calories over budget and not gain fat.

Having a break and enjoying moments of life is more important. Know that after multiple days of dieting, the tank is getting empty and eating significantly more on an occasion will not impact your fat loss.