Personal trainers often hear from clients that they aren’t losing weight despite a calorie deficit, aka burning more calories than consumed. What gives? It turns out there are quite a few reasons why this can happen.
How To Determine What Your Calorie Deficit Should Be For Weight Loss
Many people with a weight loss goal assume that the key is making their calorie deficit as big as possible. Certified personal trainer and registered dietitian Gabbi Berkow, RD, CDN, CPT, says that this is a common mistake.“The goal with weight loss is to lose fat and preserve muscle, so you don’t want your calorie deficit to be too large,” she says. Her advice is to aim for a calorie deficit of between 10 and 25 percent, or in other words eating 75 to 90 percent of the total calories burned in a day. “The more you exercise, the more you can eat while still being in a calorie deficit,” Berkow says. Curious as to how to figure out how many calories you burn in a day? Berkow recommends using a fitness tracker that monitors your heart rate, such as an AppleWatch, FitBit, Garmin, or Google Pixel Watch. “Your target calories for fat loss are 75 to 90 percent of the total calories you burn,” she says, adding that it’s important to make sure your protein consumption is about one gram per pound of body weight, or at least 30 percent of your targeted calories. If you don’t have a fitness wearable, there are several free calorie deficit calculators online, including Omni Calculator and National Academy of Sports Medicine. Maybe you already have figured out your calorie deficit, but sticking to it hasn’t resulted in weight loss. There are several reasons why this can happen, explained below.
Reasons Why You May Not Be Losing Weight in a Calorie Deficit
1. You’re underestimating how many calories you consume
The first reason comes down to plain old human error. Registered dietitian Alex Larson, RDN, says that there are some ingredients that people forget to take into account when counting calories. This, she says, can include cooking oils, condiments or sauces. “You don’t need to avoid them—just make sure that you’re taking them into consideration,” she says.
2. You’re gaining muscle
Both experts say that there’s another reason you may not be seeing the number on the scale go down even if you’re in a calorie deficit: Muscle is replacing the fat you’re losing. “Both fat and muscle weigh the same, but muscle is denser than fat, taking up less space,” Larson says. “If a person gains five pounds of muscle, they would look a lot different physically than if they gained five pounds of body fat.” This is why it’s important to not zero in on a specific goal weight but focus more on how you actually feel.
3. Your cortisol levels are high
“Cortisol is the body’s chronic stress hormone that increases fat storage around the abdomen, causing muscle breakdown, and increases fluid retention,” Berkow says. Scientific studies have shown that people with elevated cortisol levels have a harder time losing weight. “There also is a study that found stressed individuals burned about 100 fewer calories from the same high-fat meal as non-stressed individuals, which suggests that the body metabolizes fat much slower when under stress,” Larson says, adding to this point. Larson adds that chronically high cortisol levels can also impact eating behaviors, such as an increased appetite as well as craving foods high in sugar, fat and carbohydrates. Both experts emphasize that managing stress and getting adequate sleep are key ways to prevent chronically high cortisol levels. Additionally, Berkow says that doing too much cardio or HIIT can also raise cortisol levels. “You do not need to do HIIT workouts more than once or twice a week,” she says. Berkow says that walking, strength training, and doing low-impact workouts such as yoga or Pilates are all other ways to incorporate movement into your exercise routine.
4. Your insulin levels are high
Berkow says that high levels of insulin make fat loss a lot harder. “Rises and falls in blood sugar make cells more resistant to insulin, meaning blood sugar stays elevated and the pancreas has to pump out more for insulin to work,” she explains. “Insulin promotes fat storage as well, so persistently high levels of insulin put you in fat storage mode and can prevent fat burning.” In addition to this, Berkow says that low blood sugar can make someone feel tired and hungry, which can lead to unhealthy food choices. For these reasons, she says it’s important to consume foods that stabilize blood sugar. To do this, she says to prioritize fiber-rich foods (such as fruits, vegetables, and whole grains) because fiber slows down the breakdown of carbs to glucose (the sugar molecule the body uses for energy). “Pair a carb with between 20 and 30 grams of protein and one serving of fat,” she says. Berkow says that eating every three to five hours also helps keep insulin levels from rising.
5. You have a slow metabolism
“A larger-bodied person may have a faster metabolism compared to someone that’s smaller in size,” Larson says, adding that larger bodies require more energy to keep basic body functions going. She explains that there are several factors that impact metabolism, including age, sex, muscle mass, genetics and physical activity level. “To improve your metabolism, make sure that you’re fueling it with nutrient-rich foods such as fruits, vegetables, lean protein, whole grains and healthy fats,” Larson says. “Also, don’t skip meals. Your metabolism can adapt quickly by eating fewer calories, and if you restrict too much by skipping meals, your body will break down muscle for energy.” She also says that losing muscle mass can also negatively impact metabolism. For this reason, strength training and resistance exercises are important to incorporate into your workout routine.
6. Your diet is messing with your hormones
Often, someone will completely change the way they eat when they have a weight loss goal, committing to a buzzy, new diet. “One of the reasons why restrictive fad diets are shown to not work for weight loss long term is because they can deregulate hormone levels,” Larson says. “Trends such as intermittent fasting or keto can impact hormones such as ghrelin and leptin that regulate our appetite and thyroid.” Instead, she says to focus on losing weight gradually, which will allow your hormones time to adjust as you lose weight. Both experts emphasize that it’s important not to make your calorie deficit too big; otherwise, Berkow says the body will go into starvation mode, slowing your metabolism and making it harder to lose weight. Instead of zeroing in on calories, focus on eating nutrient-rich foods and minimizing nutrient-poor ones. Couple this with regular exercise and you will likely find yourself meeting your weight loss goals—likely without even counting calories at all! Next up, check out these effective tips for boosting metabolism.
Sources
Gabbi Berkow, RD, CDN, CPT, registered dietitian, exercise physiologist, certified personal trainer, Pilates instructor, and dancerAlex Larson, RDN, registered dietitian
