Evaluating whether repeated exposure to a smaller portion at lunch is an effective approach to reduce energy intake and if small enhancements to foods can increase meal satisfaction for a smaller portion

Combining small changes to foods to achieve a sustained decrease in energy intake: a Randomised Controlled Trial (RCT)

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN16303598

Enrollment

156

Registered

2017-11-15

Start date

2017-10-31

Completion date

Unknown

Last updated

2021-09-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Obesity Nutritional, Metabolic, Endocrine Obesity

Interventions

Participants are randomly allocated to one of three groups using a minimisation method, using a 4:1 element of chance. The groups are balanced for gender, age, predicted energy requirements and dietin

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. BMI =20 kg/m2 2. Aged between 18 and 70 3. Willing and able to eat all foods provided and to comply with study procedures

Exclusion criteria

Exclusion criteria: 1. Non-English speaking 2. Vegetarian, Vegan, has food allergies or intolerances to any of the food to be provided 3. Smokes more than 5 cigarettes a day 4. Drinks more than 14 units of alcohol per week 5. Has diabetes 6. Has a history of eating disorders 7. Is pregnant, breastfeeding, or planning to become pregnant during the study 8. Is taking medication that may influence appetite (except for oral contraceptive pills ) 9. Indicates that lunch is their main meal of the day 10. Does not indicate that they are familiar with eating sandwiches for lunch. 11. Taken part in any of the preparatory studies that informed this research previously undertaken in our laboratory

Design outcomes

Primary

Measure	Time frame
1. 24-hour energy intake is measured using the 24-hour energy intake calcuated from the consumption of meals and snacks. Participants attend the laboratory to consume an ab libitum breakfast, the fixed portion lunch and an ad libitum dinner on day one, day three and day ten of the intervention. 2. Meal Satisfaction is measured using a 100-mm Visual Analogue Scale immediately after eating the test lunch on day one, day three and day ten of the intervention 3. Meal Enjoyment is measured using a 100-mm Visual Analogue Scale immediately after eating the test lunch on day one, day three and day ten of the intervention	—

Measure

Time frame

1. 24-hour energy intake is measured using the 24-hour energy intake calcuated from the consumption of meals and snacks. Participants attend the laboratory to consume an ab libitum breakfast, the fixed portion lunch and an ad libitum dinner on day one, day three and day ten of the intervention. 2. Meal Satisfaction is measured using a 100-mm Visual Analogue Scale immediately after eating the test lunch on day one, day three and day ten of the intervention 3. Meal Enjoyment is measured using a 100-mm Visual Analogue Scale immediately after eating the test lunch on day one, day three and day ten of the intervention

—

Secondary

Measure	Time frame
Body weight is measured using scales at the start of each test day (day one, day three and day ten).	—

Countries

England, United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026