Nutritional therapy: what the research says

Diet advice is a first step for IBS, but nutritional therapy itself is barely studied. Food intolerance tests sold online are unreliable.

What a session is

A nutritional therapist gives you personal diet and lifestyle advice after asking about your health, eating habits and routine. In the UK, “dietitian” is the legally protected title for nutrition professionals regulated by the HCPC.

What the research says

• Gut comfort (IBS): UK guidelines make diet advice part of IBS care. Stricter diets, such as low FODMAP, should only come from a health professional with diet expertise. Some evidence it may help · NICE, 2017 · NHS, 2025
• Menopause: Cutting triggers such as caffeine, alcohol and spicy food may ease hot flushes. Soy-type supplements gave mixed results in small, poor-quality studies. Limited evidence · NHS, 2026 · Cochrane, 2013
• Low mood: The NHS suggests regular, healthy meals for steady energy. Omega-3 supplements had only a small effect in low-quality studies. See a GP if it lasts. Limited evidence · NHS, 2026 · Cochrane, 2021
• Sleep, stress, worry and anxiety, back and neck pain, grief: Nutritional therapy sessions have not been studied for these in the sources we use. No good evidence yet
• Food intolerance tests (IgG blood tests, hair analysis, muscle testing): UK guidelines say not to use IgG blood tests, hair analysis or muscle testing (kinesiology) to find food allergies. Home tests may mislead. Good evidence it does not help · NICE, 2011 · NHS, 2026

More on each need: Menopause wellbeing · Lift your mood

Is it safe?

Don't cut out whole food groups without advice from a GP or dietitian, as you could miss vitamins and minerals. Supplements can interact with medicines, so check with a pharmacist first. For a medical condition, see your GP or a registered dietitian. NHS, 2026 · NCCIH, 2019 · NHS, 2026

Sessions on Sissoo complement medical care and never replace it. Please don’t stop or change any treatment without talking to your doctor. If you feel very low or think about ending your life, call your local emergency number now.

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Checked 22 October 2026. Next check by April 2027. How we rate the evidence.