How can I gain weight safely?

Before you try to put on weight, check if you’re underweight. If you are, the best way to gain weight will depend on what caused you to lose weight. You may need medical treatment.

Seek advice

Get advice from your GP if you think you’re underweight. They can check if you’re a healthy weight for your height. You can also use the BMI healthy weight calculator.

Why have I lost weight?

Losing weight without trying to do so can have many causes.

If you’re underweight, your GP can check for any health conditions that may have caused you to lose weight, such as:

Eating disorders, such as anorexia nervosa (see below), can also cause people to lose weight.

Gaining weight

To gain weight, you need to eat more calories than your body uses each day. You need to do this regularly. It's not enough just to have occasional extra snacks.

Your GP can give you advice about eating healthily and making changes to your diet to help you gain weight.

Anorexia nervosa

If your GP thinks you have anorexia nervosa, you'll need an overall health assessment. The assessment may also involve other healthcare professionals.

Treatment for anorexia usually includes:

  • psychological treatment (talking to a therapist or counsellor)
  • advice about eating to help you gain weight safely

These treatments work better when they're used together rather than on their own.

You will be given advice about how to increase the amount you eat so you can gain weight safely. You'll receive help in re-establishing or developing healthy eating habits so that you can:

  • eat more food
  • eat more healthily
  • increase the nutrients and calories you get from the food you eat

You may also need to take supplements, such as multivitamins or multiminerals.

Read more about treating anorexia.

Read more answers to food and diet questions.

Further information:

Page last reviewed: 29/11/2013

Next review due: 28/11/2015