Overview
This study will investigate the effect of providing a daily ketogenic nutritional supplement in the evening for a prolonged time (4 weeks) to induce a mild ketogenic state during the night in healthy elderly (60-80 years), overweight/obese (BMI: 25-35 kg/m2) individuals with low physical activity, on 24h rhythmicity in energy metabolism as compared to a non-ketogenic, isocaloric control.
Eligibility
Inclusion Criteria:
- Aged 60-80 years
- Body mass index (BMI) 25-35 kg/m2
- Sedentary lifestyle (not more than 2 hours of structured physical activity per week in the past 3 months)
- Stable dietary habits (no weight loss or gain \> 5 kg in the past 3 months)
- Healthy (as determined by dependent physician based on medical questionnaire)
- Regular sleeping habits (7-9h of daily sleep)
Exclusion Criteria:
- Type 2 diabetes
- Participants with active congestive heart failure and/or severe renal and or liver insufficiency
- Uncontrolled hypertension
- Alcohol consumption of \>3 servings per day for men and \>2 servings per day for women
- Unstable body weight (weight gain or loss \> 5 kg in the last 3 months) or intention to lose weight
- Participants who are on an intermittent fasting diet
- Previous enrolment in a clinical study with an investigational product during the last 3 months or as judged by the investigator which would possibly hamper our study results
- Significant food allergies/intolerance (seriously hampering study meals or study product)
- Participants who do not want to be informed about unexpected medical findings
- Blood donation during or within 2 months prior to the study
- Disturbances in circadian rhythm determined with the follow criteria:
- Extreme early bird or extreme night person (score ≤30 or ≥70 on MEQ-SA questionnaire)
- Heavily varying sleep-wake rhythm
- Night shift work during last 3 months
- Travel across \> 1 time zone in the last 3 months
- High daily caffeine intake \> 400mg (more than 4 cups of coffee or energy drinks)
