In June 2019 researchers from Spain published the results of their study to assess the association of sleep duration and sleep variability on 12-month changes in weight and body size measurements in individuals undertaking a lifestyle intervention programme involving the Mediterranean diet. A total of 1,986 overweight/obese individuals (average age 65 years; 47% females) with the metabolic syndrome were included in the study. An accelerometer, a devise for detecting movement, was used to assess sleep duration and sleep variability and average weight, BMI and waist circumference measurements were recorded at the start of the study and again after the 12 months’ dietary intervention. Results showed that a those with a low degree of sleep variability had a slightly higher weight loss than those with a higher degree of sleep variability and that those who slept for 7-9 hours per night had a larger decrease in waist circumference than those sleeping between 6 hours per night.
Papandreou C et al. High sleep variability predicts a blunted weight loss response and short sleep duration a reduced decrease in waist circumference in the PREDIMED-Plus Trial. Int J Obes (Lond). 2019 Jun 19. [Epub ahead of print]