The aim of the present study is to compare the outcomes of standard care to the effects of exercise alone, and exercise combined with nutrition counseling, on post-transplantation weight gain and quality of life in renal transplant recipients (RTR). The primary outcome is subdomain physical functioning of quality of life, (SF-36 PFS).

Secondary outcomes include other evaluations of quality of life (SF-36, KDQOL-SF, EQ-5D), objective measures of physical functioning (aerobic capacity and muscle strength), level of physical activity, gain in adiposity (body fat percentage by bio-electrical impedance assessment, BMI, waist circumference), and cardiometabolic risk factors (blood pressure, lipids, glucose metabolism). Additionally it is planned to study data on renal function, medical history, medication, psychological factors (motivation, kinesiophobia, coping style), nutrition knowledge, nutrition intake, nutrition status, fatigue, work participation, process evaluation and cost-effectiveness.

Patient and graft survival in the first year after renal transplantation have improved substantially over the last decade, but long-term graft loss and patient mortality have remained high. It is increasingly recognized that the alarmingly poor cardio-metabolic risk profile in renal transplant recipients (RTR) plays a main role in long-term outcome. Improvement of long-term outcome will require specific efforts to improve cardio-metabolic profile and its complications. Importantly, the substantial increase in body weight and body fat that occurs after transplantation is a major trigger for the poor cardiometabolic profile in the RTR, including post-transplant diabetes and metabolic syndrome.

The increase in body weight is mostly fat tissue and typically around 9-10 kg. Most of this weight gain (~90%) occurs in the first year after transplantation. Recent data indicate that steroid avoidance could not prevent this early increase in adiposity. This warrants specific focus on lifestyle factors, i.e diet and physical activity. In the UMCG RTR cohort we found that a lack of physical activity was related to a worse cardiometabolic profile and was an independent predictor of mortality. Moreover, the substantial increase in fat massweight gain was strongly related to low physical activity, high intake of energy-dense drinks, low consumption of vegetables, to increased plasma triglycerides and the metabolic syndrome. The intake of salt and saturated fat was high and fibre intake was low, indicating dietary habits that deviate substantially from recommendations for a healthy diet. Thus, both physical activity and dietary habits are important targets for lifestyle intervention in RTR.

Lasting improvements in lifestyle are notoriously difficult to obtain, but in recent years substantial intervention expertise has been developed in other high risk groups including prediabetes. It is now established that for long term purposes, prevention of excessive weight gain is more effective than treatment of weight excess. Since in RTR most of the weight is gained in the first year after transplantation, prevention is a very promising approach. Moreover, data in prediabetes suggest that combined intervention targeting both diet and physical activity may be particularly effective to this purpose.

Therefore, our aim is to investigate the effects on quality of life by a combined diet-and-physical activity program in RTR in the first year after transplantation.

This randomized controlled intervention study will use a combined diet-and-physical activity approach. After hospital discharge for transplantation, 219 patients will be randomized to three either a control groups: one group, who will receive standard care, one group will be exposed to a 3-month exercise program followed by individual counselling and one group will be exposed to the exercise program + dietary or to intervention followed by individual counselling. The individual counselling is to consolidate the achieved improvements in diet and physical activity and will be provided until 15 months after inclusion. This counselling is based on theories of behavioural change and motivational interviewing. Daily physical activity is evaluated with a pedometer and dietary habits by questionnaires and food records.

Inclusion Criteria:

• Age ≥ 18 years;
• Informed Consent;
• >1 year after transplantation
• Medical approvement for participation in the study by the nephrologist.

Exclusion Criteria:

• Psychopathology;
• Severe cognitive disorders;
• Negative advice of the nephrologist and/or cardiologist.

Outcomes assessors are blinded if possible.