Blog · Diet and body composition

Sleep and weight loss: a study of 156 adults

Study of 156 adults with overweight followed for 18 months: those with more fragmented sleep lost less weight. An association, not a cause.

Updated October 20, 2026

A study published in the International Journal of Obesity (Nature group) in 2022 followed 156 adults with overweight or obesity through an 18-month behavioural weight loss programme. It measured sleep with a multisensor armband worn on the upper arm and related it to the weight lost and to adherence to the diet and physical activity recommendations.

In short: sleep was linked to the weight lost and to physical activity; not to the diet, once other factors were taken into account.

How sleep was measured

The programme prescribed a reduced-calorie diet and 300 minutes of physical activity a week. At the start and after 6, 12 and 18 months, participants wore the armband day and night for seven consecutive days. These are not continuous measurements: four weeks of measurement spread over a year and a half, in everyday life.

A couple in an elegant hotel bar in the evening: he smiles while she shows him the Digital Twin figure on her phone.

Ai-generated illustration

What they found

On average participants lost 7.7 kg at 6 months, 8.4 kg at 12 months and 7.1 kg at 18 months. Those whose sleep was less efficient, who woke more often or took longer to fall asleep lost less weight, even after accounting for age, sex, body mass index and other factors. Several sleep indices were also associated with lower odds of reaching 300 minutes of activity a week.

What they did not find

Once the other factors were taken into account, sleep was not associated with adherence to the diet, measured with three-day food records. The authors write that the study was not designed to establish cause and effect.

A habit is read in months, not in one meal.

What the authors suggest

The authors suggest that future studies test whether adding strategies to improve sleep to weight loss programmes helps people follow diet and activity better and lose more weight. Other studies have observed that short sleep changes hunger hormones: this one did not measure them.

The Digital Twin and this research

The Digital Twin lines up the data your devices write to your phone, such as steps, heart rate and sleep, and shows you how they change over time. It does not calculate risk and it does not diagnose: this research describes groups of people, not you. These are data to read together with your doctor.

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