This study examined time-of-day nutrient intake and its association with metabolic syndrome. The goal of the study was to compare a weight loss diet with high caloric intake during breakfast to an isocaloric diet with high caloric intake at dinner. Overweight and obese women (mean BMI 32.4) with metabolic syndrome were randomized into two isocaloric (1400 kcal) weight loss groups, a breakfast (700 kcal breakfast, 500 kcal lunch, 200 kcal dinner) or a dinner group (200 kcal breakfast, 500 kcal lunch, 700 kcal dinner) for 12 weeks. The results showed that the breakfast group showed greater weight loss and waist circumference reduction. Although fasting glucose, insulin, and ghrelin were reduced in both groups, fasting glucose, insulin, and HOMA- IR decreased significantly to a greater extent in the breakfast group. Mean triglyceride levels decreased by 33.6% in the breakfast group, but increased by 14.6% in the dinner group. Oral glucose tolerance test led to a greater decrease of glucose and insulin in the breakfast group. In response to meal challenges, the overall daily glucose, insulin, ghrelin, and mean hunger scores were significantly lower, whereas mean satiety scores were significantly higher in the breakfast group. Obesity (Silver Spring). 2013 March. PMID: 23512957.