A major randomised clinical trial in the United Kingdom will test whether switching to a high‑fat, low‑carbohydrate (ketogenic) diet can reduce depressive symptoms in people with bipolar disorder. The study, led by the Universities of Edinburgh and Birmingham, aims to recruit 200 participants and is funded to the tune of £7.9 million, according to the trial organisers.
What the trial will investigate
The trial, called ENERGISE‑BD, is described by its organisers as the world’s first large‑scale randomised controlled trial of nutrition as a potential new treatment for bipolar depression. It will compare two dietary approaches:
- a high‑fat, low‑carbohydrate (ketogenic) diet, and
- the NHS EatWell Guide — the United Kingdom’s standard public health dietary advice.
Researchers will assess whether either dietary strategy reduces depressive symptoms in people living with bipolar disorder, particularly those who experience persistent depressive symptoms between mood episodes (commonly referred to as bipolar depression).
“This is the world’s first large-scale randomised controlled trial of nutrition as a potential new treatment for bipolar depression,” said Daniel Smith, professor of psychiatry and trial co‑lead from the University of Edinburgh’s Institute for Neuroscience and Cardiovascular Research.
Why researchers think diet might help
Bipolar disorder is typified by episodes of mania and depression; however, many patients experience ongoing depressive symptoms that respond poorly to standard antidepressants. The trial follows a smaller study by the University of Edinburgh team that suggested a ketogenic diet could be beneficial in bipolar disorder.
Trial co‑leads said the research was developed in partnership with people who have lived experience of bipolar depression and that participants prioritise non‑pharmacological treatment options. The ENERGISE‑BD trial therefore seeks to establish whether dietary change could be a viable adjunctive or alternative approach to manage depressive symptoms.
Design and implications
Organisers say the trial is a randomised controlled design — the gold standard for testing interventions — and will evaluate clinical outcomes related to depression. If a clear benefit is shown, the findings could open a pathway toward new, evidence‑based dietary recommendations for people with bipolar depression.
| Trial feature | Detail |
|---|---|
| Participants | 200 people with bipolar disorder |
| Interventions compared | High‑fat, low‑carbohydrate (ketogenic) diet vs NHS EatWell Guide |
| Funding | £7.9 million (Wellcome) |
| Lead institutions | Universities of Edinburgh and Birmingham |
Context for South African clinicians and patients
Although the trial is UK‑based, its results will be of interest to clinicians and mental‑health services globally, including in South Africa. Dietary approaches that are low‑cost and scalable could be particularly important where access to specialist psychiatric services or newer pharmacological options is limited. However, several cautions apply:
- Evidence from one country or population does not automatically translate to another; differences in food availability, cultural eating patterns and comorbid medical conditions matter.
- Ketogenic diets can have side effects and are not suitable for everyone — they require clinical oversight, especially for people taking mood stabilisers or other psychiatric medications.
- Any change to treatment should be discussed with a treating psychiatrist, primary care clinician or dietitian rather than attempted alone.
The trial team emphasised the need for new treatment options. “We need new treatments for bipolar disorder,” said Steven Marwaha, professor of psychiatry and trial co‑lead based in Birmingham. The research is explicitly designed in partnership with people who have lived experience of the condition, reflecting patient priorities for non‑drug approaches.
South African health professionals will watch the ENERGISE‑BD results closely. If the trial demonstrates clear benefit and acceptable safety, the findings could inform clinical guidelines and stimulate local research evaluating how dietary interventions perform in South African populations and health‑system settings.
For now, individuals with bipolar disorder should continue to follow the advice of their treating clinicians. Patients considering dietary change as part of their mental‑health management are advised to consult their psychiatrist, general practitioner or a registered dietitian to assess risks, monitor medication interactions and ensure nutritional adequacy.
