Weight, BMI and insurance cover

Written by Emma Leadbetter. Reviewed by Tumaris Rahimova.

Published 2026-09-15. Last reviewed 2026-09-15. Next review due 2027-03-15.

How underwriting usually handles it

• Health, life, critical illness and income protection underwriters all use BMI bands.
• A high BMI more often leads to a loading than to a decline.
• Related conditions such as blood pressure or diabetes usually matter more than the number itself.
• Weight-loss surgery in your history is underwritten as a separate matter.

Which underwriting basis you choose changes the answer more than the condition itself does. Our guide to moratorium versus full medical underwriting explains the two routes; in short, a moratorium asks nothing up front and decides later, while full underwriting decides now and puts the answer in writing.

What is commonly excluded or limited

• Weight-loss treatment and bariatric surgery are excluded by most health insurance policies.
• Medication for weight loss is not covered.
• Complications of an excluded procedure are usually excluded too.

Nothing here is universal. Two insurers can take different views of the same history, and the same insurer can take different views on two products. The policy wording is the only thing that decides it.

What happens when you claim

• A loading applies from the start; it is not applied at claim stage.
• Non-disclosure of weight or related conditions is a common reason for a disputed claim.
• Improvements can sometimes be reviewed at renewal — ask.

Insurers must handle claims promptly and fairly and must not turn a claim down unreasonably; the rules are in the FCA’s insurance conduct sourcebook. ^[1] If you think a decision is wrong, you can complain and then take it to the Financial Ombudsman Service free of charge. ^[2] Our complaints page sets out both routes.

The NHS route

Whatever an insurer decides, NHS care is unaffected: buying or being refused insurance changes nothing about your entitlement. Treatment on the NHS follows clinical guidance rather than policy wording. ^{[5] [4]} For information and support about the condition itself, NICE guidance is a better place than an insurance site.

Questions to ask before you buy

1. If my BMI changes, will you review the loading, and what evidence do you need?
2. On a moratorium policy, exactly how far back does the look-back go, and how long must I be clear?
3. If I choose full underwriting instead, will you put the exclusion wording in writing before I pay?
4. Would the exclusion be reviewed later, and on what evidence?
5. Does the exclusion extend to related conditions and complications, or only to this one?

An adviser can answer those questions for your own history; we cannot, and we do not try to. Anyone advising you on insurance must be authorised, and you can check them on the Financial Services Register. ^[3] Free impartial guidance is also available from MoneyHelper. ^[6]