A Study Comparing the Health Effects of Two Diets Following UK Dietary Guidance in People Living With Overweight or Obesity

NCT05627570 | Completed DMC

• 1 other identifier: 151582
• Study Type: interventional
• Target: 55
• Locations: 1 country
• Sites: 1

Brief Summary

There are two parts to this study:

1. 1.The investigators will study if the benefit from eating a healthy, balanced diet depends on the types of food processing in the diet. The investigators will do this by providing participants with two diets that follow the Eatwell Guide (referred to in this study as Diet A and Diet B to avoid unblinding), but containing foods with different types of food processing, for 8 weeks each. The investigators will collect data on blood pressure, body composition, physical activity and fitness, questions regarding quality of life, mental health and wellbeing, and blood samples at the start of each diet and at 4 and 8 weeks into each diet.
2. 2.The investigators will then study whether participants are able to switch from their usual unhealthy diet to a healthy, balanced diet, and the benefits of doing so. The investigators will do this by providing participants with 6 months of personal support. The investigators will also look at what helps participants to maintain a healthy diet, and what makes it difficult. The investigators will also support participants to be more physically active.

Conditions

Obesity; Cardiometabolic Syndrome; Overweight

Keywords

Food processing; Diet; Healthy, balanced diet; Dietary guidelines; Obesity; Cardiometabolic disease

Outcome Measures

Primary Outcomes (1)

• Mean difference in percent weight change (%WC) at 8 weeks between Diet A and Diet B

  %WC will be calculated using: %WC = ((weight at baseline - weight at timepoint after baseline)/weight at baseline) x 100, calculated at each intervention endpoint. Mean difference in percent weight change will be calculated as: percent weight change diet A - percent weight change diet B. Weight measured in kilograms.

  Baseline to 8 weeks for both diets

Secondary Outcomes (65)

• Changes in waist circumference at 8 weeks between Diet A and Diet B

  Baseline to 8 weeks for both diets

• Changes in waist circumference after 6-months of the behavioural support programme

  First baseline to 6-months follow-up

• Changes in fat-free mass at 8 weeks between Diet A and Diet B

  Baseline to 8 weeks for both diets

• Changes in fat-free mass after 6-months of the behavioural support

  First baseline to 6-months follow-up

• Changes in fat mass at 8 weeks between Diet A and Diet B

  Baseline to 8 weeks for both diets

Study Arms (2)

Diet A then Diet B, followed by a 6-month behavioural support programme

EXPERIMENTAL

8-weeks of Diet A then 8-weeks of Diet B, then 6 months of goal-based behavioural support for consuming a healthy, balanced diet, increasing physical activity and reducing sedentary behaviour.

Dietary Supplement: Healthy, balanced Diet A; Dietary Supplement: Healthy, balanced Diet B; Behavioral: Behavioural support intervention

Diet B then Diet A, followed by a 6-month behavioural support programme

EXPERIMENTAL

8-weeks of Diet B then 8-weeks of Diet A, then 6 months of goal-based behavioural support for consuming a healthy, balanced diet, increasing physical activity and reducing sedentary behaviour.

Dietary Supplement: Healthy, balanced Diet A; Dietary Supplement: Healthy, balanced Diet B; Behavioral: Behavioural support intervention

Interventions

Healthy, balanced Diet A DIETARY_SUPPLEMENT

Healthy, balanced diet following Eatwell Guide recommendations

Diet A then Diet B, followed by a 6-month behavioural support programme; Diet B then Diet A, followed by a 6-month behavioural support programme

Healthy, balanced Diet B DIETARY_SUPPLEMENT

Healthy, balanced diet following Eatwell Guide recommendations

Diet A then Diet B, followed by a 6-month behavioural support programme; Diet B then Diet A, followed by a 6-month behavioural support programme

Behavioural support intervention BEHAVIORAL

Participants will work with a behavioural scientist to create a personal plan to eat a healthier diet and be more physically active. This support will last for 6 months, with ongoing monthly telephone/video calls with the research team.

Diet A then Diet B, followed by a 6-month behavioural support programme; Diet B then Diet A, followed by a 6-month behavioural support programme

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Staff at University College London Hospitals (UCLH)
• Adults aged between \[18 and 65\] years old.
• BMI ≥25 kg/m2 (living with overweight or obesity)
• Weight stable for the past 3 months (≤5 % variation in body weight over preceding 3 months)
• Have a habitual dietary intake high in unhealthy food
• Able to read and write in English.
• Medically safe to participate in a dietary intervention programme.
• Willing and able to give written informed consent.
• Able to attend the relevant in person and online sessions.
• Able to comply with the study protocol (including dietary recommendations for each intervention and reporting adherence).
• Females of childbearing potential and males agree to use an effective method of contraception from the time consent is signed until the end of the intervention period and final follow-up assessment. Effective methods of contraception acceptable for this trial are outlined in Appendix 2.
• Females of childbearing potential must be on highly effective contraception and have a negative pregnancy test within 7 days of being randomised. NOTE: Participants are considered not of childbearing potential if they have undergone a hysterectomy, bilateral tubal ligation, or bilateral oophorectomy) or they are postmenopausal.

You may not qualify if:

• Contraindication for dietary intervention
• Participation in another clinical intervention trial
• Concomitant usage of medications that cause weight gain or weight loss
• Cardiometabolic comorbidities (e.g. diabetes, on insulin)
• Coeliac disease
• Inflammatory bowel disease
• A diagnosed eating disorder
• Planning a weight management programme in the next 3 months
• Any diagnosed food allergy, or other allergies which limit the ability to adhere to the intervention diet
• Dietary restrictions (e.g. vegan or vegetarian) which limit the ability to adhere to the interventions
• BMI \>40 kg/m2 or basal metabolic rate ≥2300/kcal/day (to ensure intervention diets are at least 300kcal/day greater than maintenance energy needs).
• Females who are pregnant, breast-feeding, or intends to become pregnant.
• A history of drug or alcohol abuse
• Any other factor making the participant unsuitable in the view of investigator.

Sponsors & Collaborators

• University College, London: lead
• University College London Hospitals: collaborator

Study Sites (1)

UCL

London, WC1E 6JF, United Kingdom

Location

Related Publications (3)

• Heuchan GN, Buck C, Conway R, Dicken S, Brown AC, Jassil FC, Makaronidis J, Van Tulleken C, Gandini Wheeler-Kingshott CA, Batterham R, Fisher A. Development, content and planned evaluation of a behavioural support intervention to reduce ultraprocessed food intake and increase physical activity in UK healthcare workers: UPDATE trial stage 2 study protocol. BMJ Open. 2025 Oct 29;15(10):e107435. doi: 10.1136/bmjopen-2025-107435.

  PMID: 41161844 DERIVED

• Dicken SJ, Jassil FC, Brown A, Kalis M, Stanley C, Ranson C, Ruwona T, Qamar S, Buck C, Mallik R, Hamid N, Bird JM, Brown A, Norton B, Gandini Wheeler-Kingshott CAM, Hamer M, van Tulleken C, Hall KD, Fisher A, Makaronidis J, Batterham RL. Ultraprocessed or minimally processed diets following healthy dietary guidelines on weight and cardiometabolic health: a randomized, crossover trial. Nat Med. 2025 Oct;31(10):3297-3308. doi: 10.1038/s41591-025-03842-0. Epub 2025 Aug 4.

  PMID: 40760353 DERIVED

• Dicken S, Makaronidis J, van Tulleken C, Jassil FC, Hall K, Brown AC, Gandini Wheeler-Kingshott CAM, Fisher A, Batterham R. UPDATE trial: investigating the effects of ultra-processed versus minimally processed diets following UK dietary guidance on health outcomes: a protocol for an 8-week community-based cross-over randomised controlled trial in people with overweight or obesity, followed by a 6-month behavioural intervention. BMJ Open. 2024 Mar 11;14(3):e079027. doi: 10.1136/bmjopen-2023-079027.

  PMID: 38471681 DERIVED

MeSH Terms

Conditions

Obesity; Metabolic Syndrome; Overweight

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Insulin Resistance; Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases

Study Officials

• Rachel L Batterham, Professor

  UCL, UCL Hospitals

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: To minimise unnecessary unblinding, participants will not be informed of the order in which they receive their diets, but it will likely become clear which diet they are consuming, and thus the study will not be considered to be blinded.
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: 2x2, randomised, controlled crossover trial

Study Record Dates

• First Submitted: November 11, 2022
• First Posted: November 25, 2022
• Study Start: March 1, 2023
• Primary Completion: October 14, 2024
• Study Completion: June 4, 2025
• Last Updated: June 24, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)