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The science behind weight loss

In most cases, the science behind being overweight comes down to a matter of energy balance. Excess fat is stored when people take in more energy (through food and drink) than they are using up in physical activity.

Our current environment means that it is easier to gain weight than it used to be. We have access to cheap, processed foods that are high in calories and we tend to do less physical activity in our daily lives. This has led to increasing numbers of people becoming overweight.

Shifting the Energy Balance Back
If we can reduce the number of calories that we take in, and increase our levels of physical activity, we can shift the energy balance back in favour of a healthy weight.

  • In general, most women will lose weight if they eat or drink between 1,200 and 1,500 calories per day.
  • Most men will lose weight if they eat or drink between 1,500 and 1,800 calories per day.
  • However, some people might find they will initially lose weight at a higher number of calories than this, if their starting daily intake of calories was greater to begin with.

Daily Nutritional Requirements for Weight Loss:
per day
Energy as Calories (Kcals)
Saturated Fat

Maintaining a healthy weight
When you have reached your target weight, you may need to adjust your calorie intake to ensure that your weight remains stable in a healthy weight range. Generally, a healthy weight range can be defined as a BMI of 18.5-25.

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