Patients were also told to detail their snacking habits and whether or not they ate within two hours of going to sleep.
As part of the health checkup, participants were asked seven questions about their lifestyle, including whether their eating speed was fast, normal or slow, whether they snacked after dinner three times or more a week, and whether they skipped breakfast three times or more a week.
They were specifically asked about their eating speed, which was categorised as fast, normal, or slow.
At the start of the study, some 22,070 people routinely wolfed down their food; 33,455 ate at a normal speed; 4192 lingered over every mouthful. The Guardian highlighted the limitations of the study, including the small numbers who actually changed eating speed. Researchers found out that the people that ate at a normal speed were less likely to be obese compared to the fast eaters.
Also, the terms "fast", "normal" and "slow" were used by the participants of this study just as a self-evaluation, without a strict definition of the eating speeds, and without timing the participants while eating.
The team also found people who ate their evening meal at least two hours before they went to bed three times a week were 10 per cent less likely to be overweight, which they defined as having a body mass index (BMI) of more than 25. But skipping breakfast wasnot.
"The major finding of this study is that changes in eating speed can affect obesity, BMI and waist circumference", conclude authors Yumi Hurst and Haruhisa Fukuda. "Intervening to reduce how fast one eats can be effective in preventing obesity", they said.
The researchers analyzed health insurance data from nearly 60,000 Japanese people diagnosed with Type II diabetes, a condition that affects the way the body processes glucose.
And back in January it was revealed that tucking into bacon and eggs for breakfast could also help you lose weight, thanks to the fact that high-protein breakfasts (such as eggs) help to control eating later in the day. Those who said they eat slowly fared even better.
Researchers analysed Japanese health insurance and check-up data collected between 2008 and 2013.
Eating speed and other behavior were self-reported in the study.
The study involved almost 60,000 Japanese people, and the results showed that the slow-eating group had a smaller average waist circumference, a mean body-mass index of 22.3 and fewer obese individuals.
Eating quickly has previously been linked to impaired glucose tolerance and insulin resistance.
If you tend to be a fast eater, Crowley suggests trying to practice mindful eating, in which you consciously pay attention to each bite of food you put into your mouth and notice your thoughts, feelings, and sensations. Katarina Kos, an obesity researcher from Exeter Medical School, said similar research has to be conducted in non-diabetic people to rule out a potential role for diabetes medication in weight loss or gain.