"Eating Back" Calories

While calorie tracking apps are a very useful invention that can help you lose weight and keep track of your nutritional intake, they can also make mistakes that will end up setting you back. 

Weight loss/gain, when boiled down to its most basic form, is the equation of calories in vs. calories out. There's 3,500 calories in a pound, so if your goals is to lose 1lb a week you need to burn 3,500 more calories in that timeframe than you consume through food. This is called a caloric defecit.

Many of these trackers have a "net calorie" function. What this does is take your total daily caloric allowance, and add any calories burned due to exercise onto that number. This function allows you to "eat back" your calories burned, theoretically keeping you below your alloted number needed to lose weight.

For example if you're allowed 2,000 calories in a day, but lift weights for 30min and input that into your app, it may say that since you burned 200 calories in that 30min you can now eat 2,300 calories that day.

In theory, this method works. As long as you stay in a caloric defecit (ignoring food composition), you will lose weight. So eating back those "extra" burned calories beyond your resting metabolic rate will not hurt you, and eating after exercise can make you feel better and recover quicker.

However, the problem is that most of these trackers do not have an accurate exercise tracking function. Exercise has many more factors regarding calories than food, so tracking apps as well as health watches like Apple or Fitbit cannot get an accurate reading on calories burned. Most of the time, they overestimate. This number can be anywhere from 16-93%, depending on the activity done.

What this means is, if your app tells you that you burned 400 calories while exercising, and you eat those calories back, you may actually be overeating beyond your caloric allowance, taking you out of that caloric deficit and possibly into a caloric surplus. Essentially, you won't lose the weight and may even gain some.

So, don't use that "net calorie" function!! It's good to track exercise, but when you track your calories it's best to stay at or under the original number (based on metabolic rate) before exercise or turn that setting off. It's okay to eat a little more if you do have a particularly intense workout, but overall you'll find the best results if you don't pay attention to the number given on your app or device and keep extra snacking to a minimum.