FAD - Food for ADHD and Depression
| ISRCTN | ISRCTN62698625 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN62698625 |
| Sponsor | University of Oxford |
| Funder | Baszucki Family Foundation and public crowdfunding |
- Submission date
- 18/06/2025
- Registration date
- 28/04/2026
- Last edited
- 28/04/2026
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Mental and Behavioural Disorders
Plain English summary of protocol
Background and study aims
Many people with ADHD also experience low mood. While medications and talking therapies help some, others don’t find them effective or prefer not to use them. The Food in ADHD and Depression (FAD) trial is testing whether changing your diet with the help of regular coaching can improve symptoms of ADHD and depression better than another proven dietary approach.
Who can participate?
Adults aged 18 and over of any sex or gender can take part if they have a formal diagnosis of ADHD and are currently experiencing symptoms of depression (a formal diagnosis of depression is not required). Participants need regular access to the internet and must be willing to change their diet, attend online coaching sessions, complete questionnaires and cognitive tests, and provide blood and stool samples. Some people cannot take part, including those who are pregnant or breastfeeding, have a BMI under 18.5, have type 1 diabetes, serious kidney or liver problems, follow certain diets like low-carb, vegetarian, or vegan, have eating disorders, psychosis, epilepsy, substance misuse issues, or take certain medications. A medical screening will confirm eligibility.
What does the study involve?
Participants are randomly assigned to one of two dietary programmes. Each person will have Group sessions: 45 minutes per week in an online group and One-to-one sessions: 60 minutes per week in weeks 1-2, 30 minutes per week in weeks 3-8, 30 minutes every two weeks in weeks 9-16.
Assessments include online questionnaires and cognitive tests at the start, week 6, and week 16, daily 1-minute mood and energy ratings, weekly productivity ratings, daily finger-prick tests for blood sugar and ketones, blood samples at the start and week 16 at a Randox Health clinic, and stool samples at the same two time points. There is also an optional 30-minute exit interview. The study lasts 16 weeks for each participant.
What are the possible benefits and risks of participating?
You may receive personalised dietary advice that could help improve your ADHD, mood, energy levels, and overall health. You’ll also be helping researchers explore new treatment options. Some mild side effects may occur, such as headaches, tiredness, digestive changes, minor bruising from blood tests, soreness from finger-pricks, or discomfort when answering mood questions or collecting stool samples. Support is available if needed. No serious risks are expected from either diet.
Where is the study run from?
University of Oxford, UK.
When is the study starting and how long is it expected to run for?
May 2025 to June 2029
Who is funding the study?
Baszucki Group and public donations.
Who is the main contact?
Prof Michael Browning – Principal Investigator
fad@psych.ox.ac.uk
Contact information
Principal investigator
Department of Psychiatry, Warneford Hospital, University of Oxford
Oxford
OX3 7JX
United Kingdom
 ORCID ID |
0000-0001-9108-3144 |
|---|---|
| Phone | +44 (0)1865 618316 |
| michael.browning@psych.ox.ac.uk |
Public, Scientific
Department of Psychiatry, Warneford Hospital, University of Oxford
Oxford
OX3 7JX
United Kingdom
| ORCID ID |
0009-0009-7954-8303 |
|---|---|
| fad@psych.ox.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Interventional randomized controlled trial |
| Secondary study design | Randomised controlled trial |
| Scientific title | Diet and coaching for the management of attention deficit hyperactivity disorder and related depression symptoms: a 16 week randomised controlled intervention efficacy study and wider mechanistic analysis |
| Study acronym | FAD |
| Study objectives | This study explores how diet influences ADHD symptoms, mood, and mental well-being. Many people with ADHD struggle with focus, energy levels, and emotional regulation, and research suggests that nutrition might play a role in these challenges. The study aims to understand whether dietary coaching can improve ADHD symptoms and overall mental health by comparing two different dietary approaches. The study aims to: 1. Investigate whether dietary changes improve ADHD symptoms such as focus, impulsivity, and energy regulation. 2. Explore whether a low-carbohydrate ketogenic diet (KD) affects mood, productivity, and mental clarity in adults with ADHD. 3. Compare the ketogenic diet with a control diet (Hormesis Diet, HD) to determine if improvements are due to diet-specific effects or general lifestyle changes. 4. Assess biological markers (e.g., blood ketones, glucose, lipids) to understand how metabolism relates to ADHD symptoms. |
| Ethics approval(s) |
Submitted 01/05/2025, University of Oxford MS IDREC Ethics Committee (Research Services, University of Oxford, Boundary Brook House, Churchill Drive, Headington, Oxford, OX3 7GB, United Kingdom; +44 1865 (6)16577; ethics@medsci.ox.ac.uk), ref: 1090731 |
| Health condition(s) or problem(s) studied | ADHD and related depression symptoms |
| Intervention | Current interventions as of 28/04/2026: The study lasts 16 weeks. 100 adults with ADHD will be randomly assigned to one of two diet groups: Ketogenic Diet (KD) Coaching Group (low-carb, high-fat diet). Hormesis Diet (HD) Coaching Group (control diet, used as a comparison). Participants will receive weekly coaching sessions (group + individual) to help them follow their assigned diet. Participants will complete self-reported mental health and productivity assessments. Metabolic health will be monitored through blood testing. The intervention consists of online coaching on how to use and maintain a ketogenic diet for mental health. Compliance will be assessed by monitoring blood ketone levels. Participants in this arm will meet with their coach online using Microsoft Teams video conferencing software. They will be offered 45 minutes per week in an online group, and 60 minutes per week in weeks 1-2, 30 minutes per week in weeks 3-8, 30 minutes every two weeks in weeks 9-16 week one to one online with their coach. Sessions will provide information about using ketogenic diet for mental health, and coaching to encourage participants to set and maintain goals. The comparator arm will receive time-matched online coaching from a dietitian on how to use and maintain the Hormesis Diet for mental health. The comparator arm will have access to an Oxford university hosted webpage detailing the Hormesis Diet. Compliance for both arms will be assessed by monitoring daily fasted capillary blood beta-hydroxybutyrate (BHB) and glucose readings using a Keto-Mojo device, in addition to self-reported adherence discussed during weekly coaching sessions. Participants in this arm will meet with their dietitian online using Microsoft Teams video conferencing software. They will be offered 45 minutes per week in an online group, and 60 minutes per week in weeks 1-2, 30 minutes per week in weeks 3-8, 30 minutes every two weeks in weeks 9-16 week one to one online with their coach. Sessions will provide information about using the Hormesis Diet for mental health, and coaching to encourage participants to set and maintain goals. The aim is not to blind participants to the different names of the diet in their arm, but to foster equivalent enthusiasm in the prospect of their diet to improve their mental health. Previous interventions: The study lasts 16 weeks. 100 adults with ADHD will be randomly assigned to one of two diet groups: Ketogenic Diet (KD) Coaching Group (low-carb, high-fat diet). Hormesis Diet (HD) Coaching Group (control diet, used as a comparison). Participants will receive weekly coaching sessions (group + individual) to help them follow their assigned diet. Participants will complete self-reported mental health and productivity assessments. Metabolic health will be monitored through blood testing. The intervention consists of online coaching on how to use and maintain a ketogenic diet for mental health. Compliance will be assessed by monitoring blood ketone levels. Participants in this arm will meet with their coach online using Microsoft Teams video conferencing software. They will be offered 45 minutes per week in an online group, and 60 minutes per week in weeks 1-2, 30 minutes per week in weeks 3-8, 30 minutes every two weeks in weeks 9-16 week one to one online with their coach. Sessions will provide information about using ketogenic diet for mental health, and coaching to encourage participants to set and maintain goals. The comparator arm will receive time-matched online coaching from a dietitian on how to use and maintain the Hormesis Diet for mental health. The comparator arm will have access to an Oxford university hosted webpage detailing the Hormesis Diet. Compliance for both arms will be assessed by monitoring daily fasted capillary blood beta-hydroxybutyrate (BHB) and glucose readings using a Keto-Mojo device, in addition to self-reported adherence discussed during weekly coaching sessions. Participants in this arm will meet with their dietitian online using Microsoft Teams video conferencing software. They will be offered 60 minutes per week in an online group, and 30 minutes per week one to one online with their coach. Sessions will provide information about using the Hormesis Diet for mental health, and coaching to encourage participants to set and maintain goals. The aim is not to blind participants to the different names of the diet in their arm, but to foster equivalent enthusiasm in the prospect of their diet to improve their mental health. |
| Intervention type | Behavioural |
| Primary outcome measure(s) |
ADHD symptoms measured using the Adult Attention‑Deficit/Hyperactivity Disorder Self‑Report Scale (ASRS) at baseline and end of week 16 |
| Key secondary outcome measure(s) |
1. Metabolic wellness is measured using daily fasted capillary β‑hydroxybutyrate (BHB) and blood glucose (BG) readings with a Keto Mojo device, and venous mitochondrial‑driven Metabolic Dysfunction Risk Testing (MitoGENE), advanced lipid panel, and comprehensive metabolic panel at baseline and end of week 16 |
| Completion date | 22/06/2029 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 99 Years |
| Sex | All |
| Target sample size at registration | 100 |
| Key inclusion criteria | 1. Has a previous diagnosis of ADHD given by a UK psychiatrist 2. Scores 14 or more on Part A of the ASRS 3. Scores 5 or more on the PHQ-9 test, either with or without a previous depression diagnosis 4. Willing and able to give informed consent for participation in the trial 5. Male or female, aged 18 and over 6. In the Investigator’s opinion, is able and willing to comply with all trial requirements 7. Willing to allow his or her General Practitioner and consultant, if appropriate, to be notified of participation in the trial |
| Key exclusion criteria | 1. Female participant who is pregnant, lactating or planning pregnancy during the course of the trial 2. Significant known history of renal or hepatic impairment 3. Scheduled elective surgery or other procedures requiring general anaesthesia during the trial 4. Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participant at risk because of participation in the trial, or may influence the result of the trial, or the participant’s ability to participate in the trial 5. Already on a ketogenic, low carbohydrate (under 100g per day), vegetarian, or vegan diet 6. Has been diagnosed with anorexia nervosa or bulimia 7. Low BMI (<18.5kg/m²) 8. Has a bipolar disorder or schizophrenia diagnosis, or has experienced psychosis 9. Has type 1 diabetes 10. Acutely suicidal, and/or has engaged in self-injurious behaviour within the past two months 11. Active substance misuse or alcohol dependence, defined as scoring two or more on the CAGE questionnaire, any use of class A drugs in the past three months, or any use of cannabis in the last month 12. Has serious food allergies (experiencing food hypersensitivity that leads to anaphylaxis or other severe symptoms, which may require hospitalisation or are life-threatening) or otherwise requires a special diet that cannot be accommodated within a ketogenic diet, such as phenylketonuria 13. Treated with insulin, sulfonylureas, meglitinides, GLP-1 analogues, or SGLT2 inhibitors 14. Has gallstones, cholecystectomy, cachexia, porphyria, renal tubular acidosis, kidney stones, small bowel malabsorption, or a history of pancreatitis 15. Has no access to cooking facilities or ingredients to make appropriate recipes |
| Date of first enrolment | 01/04/2026 |
| Date of final enrolment | 01/02/2027 |
Locations
Countries of recruitment
- United Kingdom
Study participating centre
Oxford
OX3 7JX
England
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan | All information obtained during this study, including personal information, questionnaire/task responses, and blood and stool sample results will be kept strictly confidential and will not be shared with anyone outside the study. Electronic data for analysis will be stored on secure servers that only the principal investigator, project coordinators, and research team have access to. Data from which participants cannot be identified will be posted on the Open Science Framework, which means it will be accessible by anyone interested in analysing the data - participants will not be identifiable from this data. Identifiable data will be permanently destroyed at the end of the study. • Repository: Open Science Framework (OSF) • Type of data: Deidentified participant-level data • Process for access: Publicly available - no access request required • Timing: Available after publication of primary results • Consent: Participants consent to deidentified data being shared publicly • Anonymisation: All data will be fully anonymised before upload; participants will not be identifiable • Ethical/legal restrictions: None beyond standard anonymisation • Persistent weblink: Will be provided once the OSF project is created |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Protocol file | version 1.1 | 12/01/2026 | 09/03/2026 | No | No |
Additional files
- 47516FAD Study Protocol v1.1 12Jan2026.pdf
- Protocol file
Editorial Notes
28/04/2026: The interventions were updated.
09/03/2026: Trial's existence confirmed by University of Oxford MS IDREC Ethics Committee.
