Are you among the half of all Americans who use an activity tracker? Do you use an app like MyFitnessPal to track food and exercise? If so, you may wonder if you should be eating back exercise calories
Believe me, I get why it’d be appealing to do so. As a foodie, I’d love it if had a good reason to indulge in more the foods I enjoy. However, it’s best not to adjust calories to reflect your energy expenditure during exercise if you want to lose weight.
What Does it Mean to Eat Back Exercise Calories?
To understand why exercise calories matter in the context of nutrition, it’s helpful to know how we calculate calorie needs.
Your total daily energy expenditure (TDEE) is determined by four factors:
- Your basal metabolic rate, which is the amount of energy you burn just by existing. This rate is determined by your height, your weight, your age, your sex, and your ratio of lean mass to body fat. In some cases, acute and long-term health conditions (such as hypo- or hyperthyroidism or fever) can affect BMR.
- Did you know that you burn calories by eating? Your body works hard to digest and metabolize foods, and the thermic effect of food (TEF) describes calories burned during this process.
- Non-exercise energy thermogenesis (NEAT) refers to calories you burn during non-structured physical activity. This can be anything from walking around the house to jittering your foot when you sit. People with more active and physical jobs tend to have higher NEAT.
- Thermic effect of activity (TEA) is exercise. This is what we are talking about when we say, “eating back exercise calories.”
Weight loss occurs when you consistently burn more calories than you take in. This is mostly accomplished through diet. While exercise has so many amazing health benefits—ranging from disease prevention to socialization to improved mental health—studies show that it’s not as effective as diet for weight loss.
That said, it’s become common (partly due to apps like MyFitnessPal) for dieters to eat less on days they don’t work out, earning back calories based on estimated energy expenditure during exercise (TEA). People who do this are effectively basing their daily calorie needs on BMR + TEF + NEAT, and then adding TEA calories in direct proportion to how many they burned.
Sounds complicated, no? Without meaning to, we’ve just highlighted one reason not to use this approach—it’s a huge pain in the ass. But the reasons not to eat back exercise calories extend beyond convenience. Let’s look at a few of those now, and then we’ll discuss how to calculate your calorie needs.
Why You Shouldn’t be Eating Back Exercise Calories
There are a couple of key reasons why you shouldn’t be eating back exercise calories.
Reason 1: Your Tracker is Probably Wrong
Let me start by saying, I think many people could benefit from using activity trackers. I love how they encourage lifestyle activity by tracking steps, and in some cases by sending gentle reminders to get off your butt.
Let’s say you burned 350 calories during one of our classes, according to your device, and adjusted your calorie intake accordingly. A 93% overestimation means that you’d be eating 326 more calories than you needed. This will certainly derail your weight loss efforts and may even cause weight GAIN.
But wait, there’s more!
Reason 2: Focusing on Calorie Burn May Lead to Diet Compensation
Have you ever suffered through a long workout and thought, ”I’ve earned (insert favorite decadent food here).” Don’t be ashamed—I’ve done it too!
Studies on this topic are mixed, but it appears that some people may be more naturally prone to eat more after exercise. Some people do this simply because they’re hungrier, but others appear to eat more because they believe they burned more calories than they actually did (3).
Forget about calorie burn—focus on the other health benefits of exercise instead
Reason 3: Your Daily Calorie Target May Already Include Exercise Calories
There are a few different ways to calculate calorie needs.
Our nutrition coaches utilize advanced biometric technology (specifically, the InBody) to measure body composition and metabolic rate and add calories back for exercise. If you’re eating back exercise calories back based on what your Apple Watch says you burn during class, you’re effectively double dipping. You’ll be eating more than you need to reach your goals.
Other popular predictive equations and online calculators also factor TEA into their calorie estimates.
A Better Approach to Calculating Weight Loss Calories
A simpler and more effective approach to determining calorie needs is to use a TDEE calculator, then subtract a set number of calories each day. In most cases, I recommend starting with a 10% cut from your TDEE (for example, 1440 calories per day every single day regardless of exercise if your TDEE is 1600 calories).
However, your needs may be different based on your TDEE, your experience with following a meal plan, your workout routine, and various other factors. You might need to adjust your calorie goal if you’re losing too fast or too slow, or if your energy or performance declines.
Need a little help calculating your calorie needs and making a meal plan to help you reach your goals? Our nutrition coaches would love to help! Click here to book a free nutrition consult.