Prevention & life stages

Healthy Weight and BMI

A healthy weight lowers the risk of many diseases. BMI and waist size are useful guides, though they are not perfect for everyone.

Written by Meds Global Health Clinical Team · Clinically reviewed by Dr Muhammad Suffyan, MB BS, Founder & Clinical Director · Last reviewed · How we review

What it means

Body mass index (BMI) is a measure of weight relative to height, used to estimate whether you are a healthy weight. Waist measurement adds information about fat carried around the middle, which particularly affects health.

Why it matters

Carrying excess weight, especially around the middle, raises the risk of type 2 diabetes, heart disease, stroke, several cancers and joint problems. Reaching and keeping a healthier weight reduces these risks and benefits energy and wellbeing.

Practical tips

How to make it work

  • Check your BMI: for most adults, 18.5–24.9 is in the healthy range (adjusted ranges apply for some ethnic groups).
  • Measure your waist — health risk rises with a larger waist, regardless of BMI.
  • If you need to lose weight, aim for gradual, sustainable change through balanced eating and activity.
  • Focus on healthy habits and how you feel, not just the number on the scales.
  • Get support from a healthy-weight programme, app or your GP if you need it.
  • For children, use growth charts and seek advice rather than adult BMI.

Good to know. BMI is a useful screening tool but does not suit everyone — very muscular people, some ethnic groups, older adults, children and pregnant women need different interpretation. Waist size and overall health matter alongside it.

Answers

Healthy Weight and BMI: frequently asked questions

What is a healthy BMI?

For most adults, a BMI of 18.5 to 24.9 is considered healthy, 25 to 29.9 overweight, and 30 or more obese. Lower thresholds apply for some ethnic groups, and BMI is only a guide, not a diagnosis.

Is BMI accurate for everyone?

No. BMI does not account for muscle, fat distribution, age or ethnicity, so it can be misleading for very muscular people, older adults and others. Waist measurement and overall health should be considered alongside it.

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Education and reference only. This is general UK health guidance, not personal medical or dietitian advice. If you have a health condition or specific needs, check with your GP, pharmacist or a registered professional before making big changes.

Sources

Where this is drawn from

  • NHS — Live Well & Start for Life
  • UK Chief Medical Officers’ guidance
  • British Dietetic Association (BDA)

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