Weight loss is often described as “simple, but not easy.” Fitness experts preach that all it takes to lose weight is to use more calories than you burn, but the weight loss field is rife with misconceptions and outright falsehoods. Here are the facts when it comes to calorie deficits and weight loss:
1. Fiction: Calorie deficits won’t lead to weight loss.
To really get to the bottom of this one, it’s important to understand how the body stores fat. Fat serves multiple purposes within the body — it protects and insulates bones, joints, and organs, and serves as a kind of backup energy storage.
When an animal takes in more energy than it can use at one time, the body stores that excess as fat. There are many different factors that can influence how and where fat is stored, but fat is calorie storage. Medical conditions that contribute to weight gain do so by lowering the number of calories that the body needs to operate, but there is no condition that can create fat out of nothing. When a body burns more calories than it needs, it turns to fat stores to make up the difference.
2. Fiction: A calorie deficit will trigger starvation mode.
Ideas about starvation mode came about as a misconception of what the body goes through during severe, prolonged food deprivation. When body fat drops very low, the body begins shutting down vital processes in order to conserve energy and stay alive. A person of average or above-average weight who experiences a calorie deficit will not enter starvation mode as long as they have body fat available as a backup. Fat is energy storage, and the body wouldn’t hold onto it if it didn’t intend to use it.
In reality, the popular conception of starvation mode actually describes what happens when a person’s metabolism adjusts to weight loss. A 35-year-old, 5’10”, 400-pound man requires 2,756 calories each day just to live, even if he doesn’t exercise, move, or do anything else. A 35-year-old, 5’10”, 160-pound man, by contrast, only requires 1.667 calories for the same level of activity. This isn’t due to starvation mode, it just takes less energy to operate a smaller body than it does a larger one.
3. Fiction: Fat loss is the same as weight loss.
Fat is energy storage, but your body needs more than just raw calories in order to keep operating. If a person attempts to lose weight by eating a diet that’s deficient in protein, they’ll still lose weight — but not all of it’s going to be fat. In order to maintain and repair itself, the body will break down and use other tissues to make up for what it’s lacking in its diet. Eating at a calorie deficit will result in weight loss, but, without exercise and a balanced intake of macronutrients, only a portion of that will be fat loss.
4. Fiction: A bigger calorie deficit is better.
While a larger calorie deficit might cause the body to burn more fat in order to keep functioning, bigger isn’t better. Experts generally recommend starting with a moderate deficit of 200-300 calories per day — that’s about as much as a handful of jelly beans, or half of a muffin. This can help spur weight loss without creating feelings of deprivation. When people are deprived, they end up trying to soothe those feelings with “cheat days,” and could end up consuming enough calories in a single day to offset their entire deficit for a week.
5. Fiction: You only have to cut calories until you lose weight.
This is the number one reason why so many people say diets don’t work. In truth, any diet will work — but you have to stick to it. If a person loses weight and then resumes their old eating and exercise habits, they will regain the weight they’ve lost. If the 400-pound man in the earlier example eats at a 300-calorie deficit and loses weight, he’ll have to recalculate his body’s new calorie needs. Ideally, a diet plan should help followers develop new eating habits that lead to long-term, sustainable weight loss.
If a human eats fewer calories than their body and activity levels require, they will lose weight. There are many reasons why that weight loss might not immediately show up on a scale, however. If you’re following a sensible diet and active lifestyle and not seeing any weight loss, talk to your doctor to fine-tune your plan.