New Study: Losing Just 90 Minutes of Sleep May Lead to Weight Gain

Can losing just a little sleep each night really affect your health? According to new research from Columbia University, the answer is yes. Scientists found that reducing sleep by just 90 minutes per night may contribute to weight gain while negatively affecting daily habits and metabolic health.

The study followed nearly 100 adults who typically slept between seven and eight hours each night. Over a six week period, participants were asked to delay their bedtime by 90 minutes while keeping the rest of their daily routines the same.

The results showed that although participants were awake for longer, they did not become more active. Instead, they spent an average of 17 additional minutes each day sitting or being inactive. Among men and postmenopausal women, sedentary time increased by about 30 minutes per day.

By the end of the study, participants had gained an average of about half a kilogram. While the researchers noted that this was only a modest short term increase, they warned that maintaining this sleep pattern over time could lead to more substantial weight gain and raise the risk of obesity.

How Sleep Loss Affects the Body

Throughout the study, researchers monitored participants using smartwatches and measured changes in body weight, waist circumference, and hormones that regulate hunger and fullness.

The findings add to a growing body of research showing that chronic sleep deprivation can increase insulin resistance, raise inflammation throughout the body, and elevate the risk of developing heart disease and diabetes.

Why Does Lack of Sleep Cause Weight Gain?

According to the researchers, one of the main reasons is that insufficient sleep increases levels of ghrelin, the hormone that stimulates hunger. Higher ghrelin levels can lead to stronger cravings for foods that are high in calories, fat, and sugar.

At the same time, fatigue often leaves people feeling less motivated to exercise or even move around during the day, reducing the number of calories they burn.

Based on these findings, the researchers recommend that adults aim for between seven and nine hours of sleep each night to support overall health and help maintain a healthy weight.