Increasing evidence suggests that meal timing affects metabolic health. For example, intermittent fasting (IF) may have positive effects on plasma glucose and lipid levels, insulin sensitivity, and blood pressure. However, IF protocols often result in significant weight loss. Therefore, it is not clear to what extent these beneficial metabolic effects are due to IF or to weight loss. Although the effect of IF independent of weight loss has been studied, daily energy intake in those studies did not differ between the days. Therefore, the investigators aim to examine the effect of alternating energy intake - i.e. standardised day-to-day fluctuations in energy intake - on metabolic health independent of weight loss.

Inclusion Criteria:

• Apparently healthy men and women as judged by study physician
• Abdominally obese males (waist circumference ≥ 102 cm) and females (waist circumference ≥ 88 cm)
• Aged between 18 - 75 years
• Stable bodyweight (weight gain or loss ≤ 3 kg in the past three months)
• Willingness to give up being a blood donor (or having donated blood) from 8 weeks before the start of the study, during the study and for 4 weeks after completion of the study
• No difficult venipuncture as evidenced during the screening visit
• Women should be pre- or postmenopausal
• Sedentary (light exercise < 1 h per week) or moderately active (moderate exercise 1-2 h per week)
• Having a general practitioner
• Agreeing that the participant and general practitioner will be informed about medically relevant personal test results by a physician
• Willing to comply to study protocol during study
• Informed consent signed

Exclusion Criteria:

• Fasting plasma glucose ≥ 7 mmol/l
• Fasting serum triacylglycerol ≥ 4.5 mmol/l
• Fasting serum total cholesterol ≥ 8 mmol/l
• Blood pressure ≥ 160/100 mm Hg
• Current smoker, or smoking cessation < 12 months
• Drug abuse
• Alcohol abuse (≥ 21 alcohol consumptions per week)
• Use of medication known to affect blood pressure, serum lipid metabolism, or glucose metabolism
• Having a medical condition or history which might impact study measurements, to be judged by the study physician (e.g. myocardial infarction, angina, thrombosis, stroke, cancer, familiar hypercholesterolemia, liver or bowel disease or diabetes)
• Active cardiovascular disease like congestive heart failure or cardiovascular event, such as an acute myocardial infarction or cerebrovascular accident
• Use of an investigational product within another biomedical intervention trial within the previous 1-month
• Women who are perimenopausal, have an irregular menstrual cycle, or are pregnant
• Use of over-the-counter and prescribed medication, which may interfere with study measurements (to be judged by the principal investigator), e.g. weight loss medication
• Reported dietary habits: medically prescribed diets or slimming diets
• Reported participation in night shift work 2 weeks prior to screening and/or during the study. Night work is defined as working between midnight and 6.00 AM