If you want to lose weight, you might think you need to count calories and eat less, right? Well, that’s not necessarily true, says Terry Fairclough, a top personal trainer and co-founder of Your Body Programme.

As a personal trainer, I’ve heard countless opinions and questions about the best diet for weight loss. Should we be counting calories? How many should we eat? Should we focus on a low fat, low carb, or high protein diet? Should we be fasting or eating small, regular meals three times a day?

While these questions have their place depending on your body type, goals, and activity levels, the one thing you shouldn’t do is undereat. We all know someone who decides to count calories and drastically cut back to get “beach body ready,” thinking the weight will just melt away. Well, that might happen, but it’s not the best outcome.

A calorie deficit can lead to weight loss, but it won’t necessarily lead to fat loss, which is usually the real goal. Many people do need a slight calorie deficit because they were probably overeating before. However, undereating isn’t the way to lose weight effectively.

When we eat, our bodies break down carbs into glucose, a type of sugar that fuels our cells. If we don’t burn this glucose through activity, it’s stored in our muscles and liver as glycogen, which attracts water. When you cut calories, what you’re losing initially is stored carbohydrate and water, not fat.

In fact, a prolonged calorie deficit causes your body to hold onto fat and break down muscle protein instead. Protein is vital because it helps you burn more fat at rest. So, it’s crucial to eat enough calories with a balanced mix of fats, carbs, and protein.

You might think cutting out fat helps you lose weight, but that’s not true. Fat is a vital and long-lasting energy source, offering more than twice as much potential energy as carbs or protein. It’s also stored in muscles and easily accessed during exercise. So, cutting out fat means you won’t have the energy for workouts, hindering your weight loss efforts.

Restricting calories and essential nutrients can lead to nutrient deficiencies, affecting your immune system, liver, digestion, and overall health. Issues like fatigue, malnutrition, osteoporosis, anemia, hormonal problems, and fertility issues can arise. Extreme calorie cutting also increases stress, leading to the release of cortisol, a hormone that can cause weight gain over time.

High cortisol levels slow your metabolism, cause your body to store fat, especially around the belly, and can even lead to thyroid issues. Stress also affects digestion, making it harder to absorb the nutrients you need, impacting your training and results.

Lack of calories can also ruin your sleep. When blood sugar levels drop, stress hormones like adrenaline kick in, waking you up and affecting your overall health.

Bodybuilding competitors often cycle calories but can become ill if they do it wrong. Constantly cutting calories puts your body into “famine mode,” making it store fat and slowing your metabolism, making weight loss harder.

The bottom line is to eat the right amount of calories, carbs, fat, and protein based on your specific body type, goals, activity level, height, weight, and age. Your Body Programme (YBP) can help determine your needs.

Focus on eating plenty of lean proteins, healthy carbs from fruits and vegetables, and healthy fats like avocado and nuts. This balanced approach fuels your metabolism and supports overall health.

Terry Fairclough is a co-founder of Your Body Programme, a Personal Trainer, and a Nutritional Therapist. He believes in healthy, balanced eating to achieve your fitness goals.