If you’re trying to lose weight, you might think counting calories and eating less is the way to go. But that’s not always the case, says Terry Fairclough, a personal trainer and co-founder of Your Body Programme. As a trainer, I’ve heard countless opinions about the best diet for weight loss. Should we count calories? Go low fat, low carb, or high protein? Should we fast or eat small, regular meals throughout the day?

Here’s the thing: a big calorie deficit might help you drop pounds, but it’s not necessarily losing the kind of weight you want—like body fat. In the Western world, we typically consume more than we need, so a slight calorie cut is often needed. But the misconception is that under-eating is the only way to shed pounds, and that’s simply not true.

When you eat, your body breaks down carbs into glucose, which fuels your cells. If it’s not used immediately, it’s stored as glycogen in your muscles and liver. This is important because when you restrict calories, you’re mainly losing stored carbs and water—not fat. In the long run, a calorie deficit can cause your body to cling to fat and break down protein instead, which isn’t ideal.

Protein is biologically active, so the more you have, the more fat you burn while resting. That’s why it’s crucial to eat enough of all three macronutrients—fats, carbs, and protein. Contrary to popular belief, your body needs fat. It’s a vital energy source, providing more than double the energy of carbs or protein. Fat is stored in muscle fibers and can be accessed easily during exercise. Eliminating fat from your diet won’t give you the energy needed to shed the excess fat.

Cutting calories and restricting nutrients can also make you prone to deficiencies, affecting everything from your immune system to metabolism. Issues include fatigue, malnutrition, osteoporosis, anemia, depression, and more. Extreme dieting stresses your body and can lead to issues like increased cortisol, a stress hormone that, over time, causes fat gain, especially around the belly. It slows your metabolism, affects your thyroid function, and hampers digestion.

Eating too little can also disrupt sleep as low blood sugar levels trigger the release of adrenalin, another stress hormone, which can wake you up. Poor sleep affects everything from liver function to exercise performance, ultimately leading to weight gain. I’ve met bodybuilders who restrict calories to get lean but often fall ill from doing it incorrectly.

Eventually, you can’t cut more calories without causing harm. Your body enters a “famine mode,” storing everything above the minimal intake as fat. It’s crucial to consume the right amount of calories, carbs, fats, and protein tailored to your body type, goals, activities, height, weight, and age.

At Your Body Programme, we help people determine their ideal calorie intake based on their body types. It’s about being healthy and nourished while keeping your metabolism active. Surprisingly, increasing your calories can help you lose fat. Focus on lean proteins like chicken, fish, and tofu; healthy carbs like fruits, veggies, and whole grains; and healthy fats like avocados and nuts.

Overall, it’s about understanding your body and giving it what it needs to thrive without drastic cuts and restrictive diets.