Cortisol belly and stress weight gain, assessed in London

Cortisol belly is a name from social media rather than a diagnosis a doctor would write down. It usually describes weight that settles around the middle during a stressful stretch of life, and the phrase suggests a hormone is to blame. Cortisol is a real stress hormone, and a condition that makes the body produce far too much of it does exist, but the NHS describes it as rare.

For most people the honest explanation is less dramatic and more useful: stress costs sleep, poor sleep changes what and when you eat, and a busy year cuts the activity that used to balance it. Those are things an assessment can measure and a plan can change.

• Poor sleep: the NHS says it can make you more likely to choose high calorie foods
• Being too tired to exercise or to cook, which the NHS also links to poor sleep
• Less activity during a demanding period at work or at home
• Midlife hormonal change: the NHS says weight gain in perimenopause and menopause often settles around the stomach
• Rarely, Cushing's syndrome, where the body has too much cortisol, which needs a GP

The NHS describes Cushing's syndrome, the condition caused by too much cortisol, as rare. Its symptoms go beyond weight around the middle: more body fat on the neck, upper back, chest and tummy while the arms and legs look thin; a red, round face; skin that bruises easily and stretch marks; muscle weakness; mood changes; and irregular periods.

If that list sounds like you, see your GP rather than any weight clinic. The NHS says the most common cause is taking high-dose steroid medicine for a long time, so mention any you take, and never stop a prescribed medicine without talking to whoever prescribed it.

The NHS says cortisol is measured from samples of blood, urine or saliva, and testing is usually arranged by a GP when someone has symptoms of Cushing's syndrome. It is not a routine test for weight gain, and one reading taken on a stressful morning says little on its own.

The bloods that do belong in a first weight management assessment are the standard panel: thyroid function, HbA1c for blood sugar over recent months, liver and kidney function, and cholesterol. They find the common, treatable causes first.

The NHS says not getting enough sleep can make it harder to lose weight, because poor sleep may make you more likely to choose high calorie foods and too tired to exercise or cook. A stressful period usually takes sleep first, which is why the two turn up together at an assessment.

A plan that starts by cutting food further, without looking at sleep, is working against the thing that is driving the eating. The first question worth answering is usually how many hours you are actually getting, not how many calories.

No exercise or food takes fat off one part of the body, so the aim is overall change, tracked at the waist. NICE advises keeping your waist to less than half your height, and a tape measure shows progress around the middle long before the scales settle.

What tends to work in a demanding year is modest and repeatable: protecting sleep, regular movement towards the NHS guide of at least 150 minutes of exercise a week, strength work to hold on to muscle, and meals planned for the evenings you know will be late. A practitioner can build those into a written plan you can actually keep.

A first private weight management assessment takes 45 to 60 minutes and looks at your weight history, sleep, stress, activity, waist and blood pressure, with bloods for the common medical causes. UNTIL Health Concierge arranges it with a registered practitioner at UNTIL Marylebone, 1 Orchard Street, which opens at 06:00 on weekdays, once you send the enquiry form. If what you describe sounds like Cushing's syndrome, the right first step is your GP, and the practitioner will say so.