Slow eating speed may be linked to weight loss

Slowing down the speed at which you eat, along with cutting out after dinner snacks and not eating within 2 hours of going to sleep may all help to shed the pounds, suggests research published in the online journal, BMJ Open.

Changes in these eating habits were strongly associated with lower obesity and weight (BMI), and smaller waist circumference, the researchers found.

The findings have been compiled from health insurance data for nearly 60,000 people with diabetes in Japan who submitted claims and had regular health check-ups between 2008 and 2013.

The claims data included information on the dates of consultations and treatments, while the check-ups included measurements of weight (BMI) and waist circumference, and the results for blood chemistry, urine and liver function.

During the check-ups, participants were quizzed about their lifestyle, including:

• Eating habits
• Sleep habits
• Alcohol consumption
• Tobacco use

They were specifically asked about their eating speed, which was categorised as fast, normal or slow. They were also asked whether they did any of the following three or more times a week: eat dinner within 2 hours of going to sleep, snack after dinner and skip breakfast.

More than a third (36.5%) of participants had one check-up over the six years, while just under a third (29.5%) had two. One in five (20%) had three.

At the start of the study, some 22,070 people routinely wolfed down their food; 33,455 ate at a normal speed; and 4192 linger over every mouthful. The slower eaters tended to be healthier and have a healthier lifestyle than the other fast or normal speed eaters.

Around half of the total sample (just under 52%) changed their eating speed over the course of six years. All the aspects of eating and sleeping habits were studied, as well as alcohol consumption. Those previously-defined as having a of BMI of 25kg/m2 were significantly associated with obesity.

After taking account of potentially influential factors, the results showed that compared with those who tended to eat faster, those who ate at a normal speed were 29% less likely to be obese, rising to 42% for those who ate slowly.

Although absolute reductions in waist circumference – an indicator of a potentially harmful midriff bulge, were small, they were greater among the slow and normal speed eaters.

Snacking after dinner and eating within 2 hours of going to sleep 3 or more times a week were also strongly linked to changed in BMI. However, skipping breakfast wasn’t.

This is an observational study, so no firm conclusions can be drawn about cause and effect, added to which eating speed was based on subjective assessment, nor did the researchers assess energy intake or physical activity levels.

Nevertheless, eating quickly has been liked to impaired glucose tolerance and insulin resistance. This could be down to the fact it may take longer for fast eaters to feel full, whereas this might happen more quickly for slow eaters, helping to curb their calorie intake, the research suggests.

They concluded: “Changes in eating habits can affect obesity, BMI and waist circumference. Interventions aimed at reducing eating speed may be effective in preventing obesity and lowering the associated health risks.”