A multi-component intervention to reduce unhealthy diets and physical inactivity among adolescents in Nairobi, Kenya, and Accra, Ghana: the Generation-H study

ISRCTN	ISRCTN15468652
DOI	https://doi.org/10.1186/ISRCTN15468652
HaDEA grant number	101095375
UKRI grant number	10106976
Sponsor	Amsterdam University Medical Centers
Funders	European Health and Digital Executive Agency, UK Research and Innovation

Submission date: 08/09/2026
Registration date: 17/09/2026
Last edited: 17/09/2026

Recruitment status: Not yet recruiting
Overall study status: Ongoing
Condition category: Other

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Background and study aims
Diet and physical activity habits formed during adolescence can influence the risk of non-communicable diseases later in life. Generation-H is testing how a programme supporting healthier diets and physical activity can be delivered through schools and faith-based organisations in urban Kenya and Ghana. The study will examine how well the programme is implemented, whether adolescent behaviours and health measures change, and what the programme costs.

Who can participate?
Adolescents aged 10-19 years living in the selected study areas in Nairobi and Accra may be eligible. Participation requires consent or assent, with parent or caregiver consent for participants below the applicable national age of consent.

What does the study involve?
The programme combines education on healthy diet and physical activity, improved access to fruits, vegetables and safe drinking water, and opportunities and equipment for physical activity. It is delivered through participating schools and faith-based organisations over 18 months. Separate samples of adolescents are invited to complete surveys and physical measurements at baseline, 6 months and 18 months. The study also uses routine programme records, interviews and focus group discussions to understand how the programme is delivered and experienced.

What are the possible benefits and risks of participating?
Participants and their communities may benefit from improved access to information and opportunities that support healthy diet and physical activity. Direct individual benefit cannot be guaranteed. Survey questions and physical measurements involve minimal risk, although some questions may feel personal and participation may take time. Participation is voluntary, information is kept confidential, and participants may withdraw without consequence.

Where is the study run from?
The study is conducted in selected urban areas of Nairobi, Kenya, and Accra, Ghana, through participating schools and faith-based organisations.

When is the study starting and how long is it expected to run for?
The household listing and baseline evaluation were completed before intervention delivery. The intervention is planned for 18 months, with evaluation surveys at baseline, 6 months and 18 months.

Who is funding the study?
The European Union through the European Health and Digital Executive Agency (grant 101095375) and UK Research and Innovation (grant 10106976).

Who is the main contact?
Dr Peter Otieno, African Population and Health Research Center. Email:potieno@aphrc.org.

Contact information

Prof Charles Agyemang
Principal investigator, Scientific, Public

Amsterdam University Medical Centres, University of Amsterdam
Amsterdam Public Health Research Institute, Department of Public & Occupational Health
Location AMC
Amsterdam
Meibergdreef 15
Netherlands

ORCID ID	0000-0002-3882-7295
Phone	+31 6 4835 3652
Email	c.o.agyemang@amsterdamumc.nl

Study information

Primary study design	Interventional
Allocation	N/A: single arm study
Masking	Open (masking not used)
Control	Uncontrolled
Assignment	Single
Purpose	Prevention
Scientific title	A hybrid type III implementation-effectiveness study of a co-designed multicomponent intervention to improve dietary and physical activity behaviours among adolescents aged 10-19 years in socioeconomically diverse urban settings in Kenya and Ghana: the Generation-H project
Study acronym	Generation-H
Study objectives	1. Evaluate the implementation of a co-designed multicomponent intervention promoting healthy diet and physical activity among adolescents in urban Kenya and Ghana 2. Assess changes in dietary behaviours, physical activity, sedentary behaviour, psychosocial measures, anthropometry and blood pressure at 6 and 18 months 3. Examine how context influences reach, adoption, fidelity, acceptability, appropriateness, feasibility, adaptation, penetration and sustainability across countries, socioeconomic settings and delivery settings 4. Estimate implementation costs and short- and long-term cost-effectiveness
Ethics approval(s)	1. Approved 08/09/2026, Amref Health Africa Ethics and Scientific Review Committee (Amref Health Africa in Kenya, P.O. Box 30125-00100, Nairobi, P.O. Box 30125-00100, Kenya; +254 20 699 4000; Esrc.Kenya@amref.org), ref: ESRC P1696/2024 2. Approved 08/06/2026, Ghana Health Service Ethics Review Committee (Research and Development Division, Ghana Health Service, P.O. Box MB 190, Accra, P.O. Box MB 190, Ghana; +233 50 3539896; ethics.research@ghs.gov.gh), ref: GHS-ERC 032/07/24
Health condition(s) or problem(s) studied	Prevention of non-communicable disease risk through healthy dietary and physical activity behaviours during adolescence
Intervention	Generation-H is an 18-month multicomponent intervention delivered through participating schools and faith-based organisations. Core components comprise: (1) education promoting healthy diet and physical activity; (2) provision and promotion of fruits, vegetables and safe drinking water, with reduced access to sugary foods and beverages; and (3) provision of physical activity equipment and structured physical activity sessions. Implementation strategies were developed through Implementation Mapping and include stakeholder engagement, training, implementation materials, technical assistance, monitoring, feedback, adaptation and sustainability planning. There is no concurrent control arm. Independent population-based cross-sectional samples will be surveyed at baseline, 6 months and 18 months. Routine monitoring, qualitative research and economic evaluation will complement the surveys
Intervention type	Behavioural
Primary outcome measure(s)	Acceptability (perceived satisfaction with the intervention and its delivery) measured using Acceptability of Intervention Measure (AIM), structured questionnaires, interviews and focus group discussions at 6 months, 18 months Adoption (initiation of planned intervention activities by participating schools and FBOs) measured using implementation-monitoring tools and adoption records at throughout intervention delivery Appropriateness (perceived relevance and suitability of the intervention) measured using Intervention Appropriateness Measure (IAM), structured questionnaires, qualitative interviews and focus group discussions at 6 months, 18 months Feasibility (perceived and observed ability to deliver the intervention) measured using Feasibility of Intervention Measure (FIM) and implementation-monitoring tools at 6 months, 18 months, throughout intervention delivery Fidelity (extent to which intervention components are delivered as planned) measured using fidelity checklists, observation checklists, implementer monthly reports and supervision tools at throughout intervention delivery Reach (proportion of the intended adolescent population exposed to intervention activities) measured using attendance registers and coverage/reach monitoring tools at throughout intervention delivery Penetration (integration of intervention activities within participating schools and FBOs) measured using implementation-monitoring tools, stakeholder interviews and routine records at throughout intervention delivery, 18 months Sustainability (potential for continued implementation beyond the study period) measured using stakeholder interviews, sustainability-monitoring tools and routine records at 18 months
Key secondary outcome measure(s)	1. Dietary behaviours including fruit and vegetable intake, sugar-sweetened beverage consumption, drinking-water intake and other prespecified dietary behaviours measured using the Generation-H adolescent questionnaire at baseline, 6 months and 18 months 2. Physical activity and sedentary behaviour including prespecified activity and sedentary-behaviour measures measured using the Generation-H adolescent questionnaire at baseline, 6 months and 18 months 3. Nutrition knowledge, self-efficacy, motivation, social support, social norms, psychosocial wellbeing, health literacy and quality of life measured using the Generation-H adolescent questionnaire and validated psychosocial scales at baseline, 6 months and 18 months 4. Height, weight, body mass index, waist circumference and hip circumference measured using the standardised Generation-H anthropometric protocol at baseline, 6 months and 18 months 5. Systolic blood pressure and diastolic blood pressure measured using the standardised Generation-H blood-pressure protocol at baseline, 6 months and 18 months 6. Food and physical activity environments including availability and accessibility of healthy food, drinking water and opportunities for physical activity measured using standardised environmental observation tools at baseline, 6 months and 18 months 7. Food expenditure, healthcare use, school/work absenteeism, implementation resource use and cost-effectiveness measured using the Generation-H adolescent questionnaire and prospective costing tools at 6 months and 18 months 8. Longer-term cost-effectiveness modelled over 5-years measured using Generation-H adolescent questionnaire, validated psychosocial scales, standardised anthropometric measurements, standardised automated blood-pressure measurements, environmental observation tools, participant cost questionnaires, administrative records, and standardised costing tools
Completion date	30/08/2028

Eligibility

Participant type(s)
Age group	Mixed
Lower age limit	10 Years
Upper age limit	19 Years
Sex	All
Target sample size at registration	3386
Key inclusion criteria	1. Aged 10-19 years at the relevant data-collection round 2. Resident in one of the selected study areas in Nairobi, Kenya, or Accra, Ghana 3. Selected through the population-based sampling frame for an evaluation survey, where applicable 4. Able to provide informed assent/consent, with parent or caregiver consent where required 5. Meets the predefined eligibility criteria for the school or FBO intervention pathway, where applicable
Key exclusion criteria	Required participant assent/consent or parental/caregiver consent cannot be obtained
Date of first enrolment	25/09/2026
Date of final enrolment	28/02/2027

Locations

Countries of recruitment

Ghana
Kenya

Study participating centres

participating schools and faith-based organisations in Kibera and Buruburu, Nairobi

Kenya

participating schools and faith-based organisations in Ga East and Ayawaso West, Accra

Ghana

Results and Publications

Individual participant data (IPD) Intention to share	No

Editorial Notes

09/09/2026: Trial's existence confirmed by Amref Health Africa Ethics and Scientific Review Committee.