Cognition of the complexity of influences on weight gain and identification of wider range of modifiable risk factors empower public health professionals to target health promotion and weight control intervention efforts where needed. Our study results are in line with recent suggestions that short (and possibly long) habitual sleep may be part of the causal pathway of obesity and other chronic diseases. This study was established in 1984 when average sleep length was longer than nowadays. Therefore, role of sleep in dietary intake and obesity control might be even more significant these days.
The following conclusions can be drawn from the KIHD study. Long sleepers had lowest fitness level, more often had history of CVD and had higher systolic blood pressure at baseline. Short sleepers were heavy smokers. Overall pattern of food consumption was similar among sleep groups at baseline; there were differences only in the intakes of total energy, monounsaturated fatty acids, vitamin D and fish. Short sleepers’ diet was poor in MUFA.
Long sleepers’ diet was rich in MUFA, vitamin D and fish, poor in folate and mean energy intake was lowest. Normal sleepers’ diet was poor in vitamin D and fish, rich in folate and mean energy intake was highest.
BMI was different among three sleeping categories at the baseline. Finnish middle-aged men with total sleep of 7-8 hours were statistically significantly leaner compared with other two groups at baseline. The body shape changes during the follow up did not either differ significantly among sleeping groups in the KIHD study. However, length of sleep did not show long term effect on likelihood to gain weight.
Because sleep is potentially modifiable health risk factor, these results might have important implications for the prevention and treatment of obesity and coronary heart diseases. With the intention of having healthier population, prevention of weight gain should focus on total caloric intake, adapting an overall healthy eating pattern, moderate physical activity and sufficient and adequate sleep.
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