Process of weight gain and loss

We need energy to carry out all of the essentials functions inside our body for survival, growth and overall wellbeing. It is also needed for us to carry out our everyday activities. We get this energy from the food we eat.

When we eat or drink, our bodies break down the carbohydrates, proteins, and fats present in the food, and convert them into energy to fuel various bodily functions, such as breathing, moving, and maintaining body temperature.

What are calories?

Calories are a measure of the amount of energy in an item of food or drink. The calorie content of food refers to the amount of energy released when that food is broken down by the body.

When we eat and drink more calories than we use, our bodies store the excess as body fat. If we consistently eat more calories than we need, we will put on weight.

The number of calories varies according to the nutritional composition of each item of food and drink we consume. The calorie content per gram of carbohydrate, protein, fat and alcohol is as follows:

Fat has twice the amount of calories per gram compared to carbohydrate and protein, which explains why if you eat foods that are high in fat, you are likely to consume more calories and gain weight.

Calorie requirements

Age, gender, physical activity levels and weight goal (maintenance, weight loss or gain) all affect how many calories you need.

Total Daily Energy Expenditure (TDEE)

It’s important to note that the calorie allowances above are just a general guide and do not give an individual guide.

For an accurate measure of how many calories you need per day, taking into account your age, sex, levels of activity and individual measurements to maintain your current bodyweight you can work out your total daily energy expenditure (TDEE).

Calorie deficit

A calorie deficit occurs when you’re consuming fewer calories than you use up in a day. When the body experiences a calorie deficit, it must find alternative sources of energy to meet its needs.

It does this by tapping into its energy reserves, which are primarily stored in the form of body fat. Over time, a sustained calorie deficit can lead to weight loss as the body uses its fat stores for energy. You can cause a calorie deficit by eating less food, burning more calories, or a combination of the two. 

Knowing your TDEE also means that you can easily calculate how many calories you need to eat in order to lose weight or gain weight.

For weight loss: