BMI and Foundayo: check your number and what it actually means
Foundayo’s UK licence is built around BMI thresholds, so here’s a proper calculator, the exact MHRA criteria, and an honest explanation of what BMI does and doesn’t tell you. Your number is a starting point for a conversation with a prescriber, never a verdict.
The Dayo BMI calculator
Works in UK Imperial, Metric, or Pounds only. Everything is calculated on your device; nothing you type is sent anywhere or stored.
BMI is weight in kilograms divided by height in metres squared. It’s a screening measure for populations, not a diagnosis for individuals, which is why the result below talks about ranges and licences rather than judgements.
Your BMI () is or above. That matches the BMI threshold in Foundayo’s UK weight-management indication without requiring an additional weight-related condition.
Note: Your recorded weight-related condition will also be reviewed by your prescriber during clinical onboarding.
Clinical next step: A registered prescriber must still verify your measurements, medical history, pregnancy status and current medicines, and decide whether treatment is safe and appropriate.
Your BMI () is between and , and you have indicated a diagnosed weight-related condition. That combination matches the initial terms of Foundayo’s UK weight-management indication.
Clinical next step: A prescriber will verify the condition, your measurements and whether treatment is safe and appropriate.
Your BMI () is between and . Foundayo’s authorised indication for weight management requires at least one weight-related condition in this BMI range.
If you have diagnosed high blood pressure, prediabetes, high cholesterol, or sleep apnoea, tick the diagnosed condition box above to update your eligibility.
What this means: Without a qualifying condition, this does not match the current licensed weight-management indication.
Your BMI () is below , so it does not match Foundayo’s current UK indication for weight management on the basis of BMI and a weight-related condition.
Important: This tool does not assess Foundayo’s separate type 2 diabetes indication or whether any treatment is suitable for you. Speak to a prescriber for an individual assessment.
Your BMI and how it relates to the UK Foundayo licence will appear here. Nothing is stored or sent anywhere.
This tool is general information, not medical advice or a prescribing decision. Thresholds are lower for some ethnic backgrounds; see below.
Last verified: 18 August 2026
The exact UK criteria for Foundayo
The MHRA authorised Foundayo, alongside a reduced-calorie diet and increased physical activity, for adults with:
- a BMI of 30 or above (obesity), or
- a BMI between 27 and 30 (overweight) plus at least one weight-related condition.
It’s separately licensed to improve blood sugar control in adults with insufficiently controlled type 2 diabetes. Weight-related conditions that typically qualify in UK GLP-1 prescribing include type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol, obstructive sleep apnoea and cardiovascular disease. The prescriber’s assessment, not a list on a website, is what decides your case; a proper consultation also screens the things a calculator never can, like your medical history, other medicines and the thyroid red flags.
Lower thresholds for some ethnic backgrounds
BMI can underestimate health risk at a given weight for people from some ethnic backgrounds. UK NICE guidance uses lower risk categories for people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background: BMI 23 to 27.4 is classed as overweight and 27.5 or above as obesity. These categories help describe health risk, but they do not rewrite Foundayo’s current authorised weight-management indication, which remains BMI 30 or above, or BMI 27 to below 30 with at least one weight-related condition. A prescriber should consider both the licence and your individual risk.
What BMI genuinely can’t tell you
Time for the honest bit. BMI is a blunt instrument: it can’t tell muscle from fat, so a rugby player and an inactive person can share a number while having completely different health; it says nothing about where fat sits, and waist measurement often predicts risk better; and it was built from population averages, which is why it needs the ethnic adjustments above. None of that makes it useless. It’s quick, free, consistent, and at population scale it tracks health outcomes well, which is why licences and guidelines are built on it. The sensible reading: treat your BMI as one signal that starts a conversation, alongside waist size, blood pressure, blood sugar and how you actually feel, and let a clinician put the picture together.
Helpful extras worth knowing
- Waist check: as a rule of thumb, a waist over half your height suggests carrying risk around the middle, whatever your BMI says. A tape measure is the cheapest health tool you’ll ever buy.
- Your BMI moves, and so does eligibility maths. Prescribers assess you at the point of prescribing; ongoing treatment reviews are normal as your weight changes.
- Travel insurance asks for BMI too. Medical screenings routinely ask current height and weight, and honesty matters because claims can be checked against records. Our travel guide covers it properly.
- NHS BMI tools: the NHS BMI calculator includes the ethnic adjustments and links to NHS weight management support, which is free and worth knowing about whatever you decide on medication.
- Beware quiz-only prescribing. A BMI typed into a form is not a consultation. Reputable providers verify identity and weight, review your history and give you a real clinician to talk to; that’s part of how you spot the good ones.
Where this fits in your decision
Eligible on paper is step one of several. What the medicine is and what the trials showed is covered in our main guide, the honest side effect picture is on the side effects map, and when UK prices land they’ll be on our retail and discount lists. Safety first, then eligibility, then price.