What doctor to see for obesity: GP, specialist or weight service

You want medical support with your weight, and you are not sure where to start. Your GP, a specialist or a weight management service? The path usually starts in primary care, and every referral adds letters and lab reports. You can keep them in a folder or in Sam's Health Vault, which, with your consent, reads values such as HbA1c, cholesterol and TSH from each lab report.

This guide sorts out who does what, when a specialist comes in and what to ask. It is written for adults. What happens at the visit and why a weight trend beats one reading is covered in Obesity appointment: bring a weight trend. What you can keep in Sam, from the symptom diary to lab reports, is on the obesity page.

What doctor should I see for obesity?

For most adults, the first stop is a GP or, in the US, a primary care provider. HealthCare.gov describes a primary care provider as someone who provides, coordinates or helps you access a range of health care services.

The NHS says a GP can give advice and refer you for support. A GP can also help you get support for other conditions that may be affecting your weight, including mental health conditions.

Doctors look at more than the scale. IQWiG's InformedHealth site says doctors often check blood pressure, blood sugar, cholesterol and kidney function. They may also measure thyroid hormones to look for a possible cause. Which tests you need is covered in the appointment guide linked above.

When is it worth booking that appointment?

The NHS lists reasons to see a GP. They apply if your BMI is in the overweight or obesity range and one of these is true:

• You want help with your weight.
• Your waist measures more than half your height.
• You have prediabetes, diabetes, high blood pressure, joint pain, high cholesterol, sleep apnoea or cardiovascular disease.
• Obesity runs in your family.
• You have, or think you may have, an eating disorder such as binge eating.

These are reasons to start a conversation, not a test to score yourself on. You can book an appointment even if none of them fits.

When does a specialist get involved?

Whether you need more than your practice offers is something your doctor decides with you. Three routes are worth knowing.

Weight management services: in the UK, if you need a lot of extra support, the NHS says you may be referred to a specialist weight management service. You can self-refer to some weight management programmes. Your GP surgery website, the reception staff or, in England, your local integrated care board can tell you what is available.

Endocrinology: a hormone specialist is not automatically needed. The European Society of Endocrinology's 2020 guideline recommends testing thyroid function in everyone with obesity. Tests for other hormone problems, such as excess cortisol or sex hormone disorders, are recommended only on clinical suspicion.

Sleep medicine: loud snoring, pauses in breathing at night and heavy daytime sleepiness can point to sleep apnoea. The NHS says a GP may then refer you to a specialist sleep clinic for tests. What to note before that visit is in Sleep apnea: what to log for your sleep doctor.

If a lab report shows a raised HbA1c, Prediabetes HbA1c: what your results mean explains the numbers and the next visit.

What is an obesity medicine specialist?

In the US and Canada, some doctors are certified by the American Board of Obesity Medicine (ABOM). To take its exam, a doctor needs, among other things, an active license, a completed residency and board certification in a medical specialty. ABOM says its certification signifies specialized knowledge in the practice of obesity medicine.

The ABOM website has a search where you can check whether a doctor is certified. Your primary care doctor or your insurer can tell you whether such a specialist is in your network.

Do you need a referral for a specialist or weight service?

It depends on your health system and your plan.

In the US, HealthCare.gov defines a referral as a written order from your primary care doctor to see a specialist. In many HMO plans, you need one before you get care from anyone except your primary care doctor. Without it, the plan may not pay.

In the UK, a GP can refer you to weight management services, including specialist ones, while some programmes take self-referrals. Ask your practice which applies where you live.

If your symptoms get worse while you wait, contact your doctor sooner. Some signs should not wait at all.

Which symptoms should not wait for a referral?

• Call your local emergency number (112 in the EU, 999 in the UK, 911 in the US) for sudden or severe breathlessness, chest pain, pale, blue or grey lips or skin, or if someone collapses. Do not wait for it to pass.
• Ask for an urgent appointment straight away if you are breathless lying down or with everyday activity. The same goes for one swollen and painful leg and for sudden weight gain. In the UK, that means an urgent GP appointment or NHS 111.
• See your doctor promptly, not at your next routine check, about swollen feet, ankles or legs. The same applies to more breathlessness on exertion than usual, loud snoring with pauses in breathing or heavy daytime tiredness. Go sooner if things get worse.

These tiers follow the NHS pages on heart failure, pulmonary embolism, DVT and sleep apnoea. They are not a diagnosis. Finding the cause is your doctor's job.

What should you ask at the first appointment?

InformedHealth suggests writing your questions down beforehand. For finding your way between services, these fit:

• Who coordinates my care, and who gets the letters from other services?
• Which tests have already been done, and which do I still need?
• Do I need a referral, and to which service?
• Is there a weight management service I can join locally?
• Which symptoms should I note before the next visit?
• When should I come back, and when should I come sooner?

You can also say which words you prefer and whether talking about weight is hard; the appointment guide covers that. If everything gets put down to your weight, When your doctor does not take your symptoms seriously helps you prepare. It also covers when a second opinion makes sense.

What paperwork helps at a specialist visit?

• Your referral letter, if your service or plan needs one.
• Letters and results from other doctors, including older ones.
• Your medication list.
• Your lab reports, so results can be compared.

The full list, with weight readings, symptoms and questions, is in the appointment guide. For any visit, the doctor appointment checklist for a chronic condition helps too.

In Sam, you add doctor's letters, specialist notes and lab reports as a scan, photo or PDF. Reading the values needs your consent. Sam maps about 33 common lab values to a fixed name. They include glucose, HbA1c, cholesterol values, uric acid, eGFR, the liver values ALT and GGT, and TSH. Other rows stay as printed. Where your lab printed a range, Sam shows whether the value sits above, below or within it. That is your lab's range, not a medical judgement.

If a report prints separate ranges for women and men, Sam keeps only the first one. The label can then be wrong. Some rows can also land under the wrong name. Check the values against the original report.

Keep letters and lab reports for every doctor in Sam

When you move between your GP, a specialist and a weight service, your paperwork sits in one place instead of several folders.

• Instead of a folder: you add doctor's letters, specialist notes and lab reports as a scan, photo or PDF. They are with you at the next visit.
• Instead of comparing sheets by hand: with your consent, Sam reads values such as HbA1c, cholesterol, TSH and liver values. It compares your last two lab reports when the units match.
• Instead of memory: you log breathlessness, joint pain or daytime sleepiness per day in the symptom diary.

Sam does not weigh you and shows no BMI; what your results mean is for your doctor to say. More on the obesity page.

Try Sam for free

Sam is a wellness companion, not a medical device. It does not diagnose, treat, cure or prevent any disease or health condition. Always consult a qualified healthcare professional for medical decisions.

Related reading

• Obesity appointment: bring a weight trend, not one number
• Doctor appointment checklist for a chronic condition
• When your doctor does not take your symptoms seriously
• Sleep apnea: what to log for your sleep doctor
• Prediabetes HbA1c: what your results mean

Sources

Updated: October 2026

• NHS: Obesity and Obesity: treatment (both reviewed 29 April 2026)
• HealthCare.gov glossary: Primary care provider and Referral
• IQWiG, InformedHealth.org: Obesity (created 22 November 2022)
• Pasquali R et al.: European Society of Endocrinology Clinical Practice Guideline: Endocrine work-up in obesity, European Journal of Endocrinology 2020; 182(1): G1-G32, doi 10.1530/EJE-19-0893
• American Board of Obesity Medicine: Certifying physicians in obesity medicine (with physician search)
• NHS: Heart failure: symptoms (reviewed 26 June 2026), Pulmonary embolism (reviewed 15 October 2026), Deep vein thrombosis (DVT) (reviewed 30 April 2026) and Sleep apnoea (reviewed 11 May 2026)