An individualised Lifestyle Intervention with Physical Activity and Diet in individuals with overweight and obesity (LI-PAD)-study protocol of a 6-month randomised controlled study {1a}.

The study targets adults aged 45-65 years with overweight or obesity defined by a specific BMI range.

• Eligible participants are men and women residing in the Gothenburg area aged 45-65 years.
• Inclusion requires a body mass index of ≥28 and <35.
• The age and BMI criteria are intended to capture a population at elevated cardiometabolic disease risk.

The trial plans to recruit 120 participants randomised 1:1 to intervention or control groups.

• The target sample is 120 females and males.
• Participants are randomly allocated in a 1:1 ratio to either the intervention or control group.
• The study will be conducted at the Centre for Lifestyle Intervention, Sahlgrenska University Hospital, Gothenburg, Sweden.

The intervention group receives a 6-month individually tailored support programme covering both physical activity and dietary modifications.

• The intervention encompasses individually tailored support and guidance on lifestyle behaviours encompassing physical activity and dietary modifications over 6 months.
• The intervention offers 'flexible support strategies' rather than a standardised protocol.
• The approach is described as moving 'beyond a one-size-fits-all strategy when tackling complex behaviour change challenges.'
• Introducing health promoters in a clinical setting is described as 'a novel approach.'

The control group receives standard written lifestyle advice based on general physical activity and dietary recommendations.

• The control group will receive 'standard lifestyle advice based on general physical activity and dietary recommendations, respectively.'
• This comparator represents a 'one-size-fits-all' approach as opposed to the individualised intervention.

The primary outcome measure is weight loss from baseline to the 6-month follow-up.

• The primary outcome measure will be weight loss from baseline to the 6-month follow-up.
• Secondary outcomes include other cardiometabolic disease risk factors and health-related quality of life.
• Critical health metrics addressed include weight, blood pressure, and physical activity.

The statistical analysis plan specifies multilevel mixed modelling for repeated measures with an intention-to-treat approach.

• Data analysis will employ multilevel mixed modelling for repeated measures.
• Linear and logistic analyses will also be used.
• The analysis will adhere to an intention-to-treat approach.

The study is prospectively registered on two registries with specific identifiers.

• The study is registered on researchweb.org on 2 January 2024 (project number 281907).
• It was subsequently registered at ClinicalTrials.gov as NCT06379802 on 9 February 2024.
• The approval number/ID is 2023-00546-01.

The study uses objective data to individualise advice, distinguishing it from standard lifestyle interventions.

• Individualised advice is described as 'based on objective data.'
• This approach is intended to address 'complex behaviour change challenges in overweight and obesity management and reducing cardiometabolic disease risk.'
• The feasibility of the intervention is listed alongside effectiveness as a primary objective.