A new study, published in the latest issue of the journal BMJ Open , has shed light on several eating habits that could be linked to obesity . Notable among these are speed of eating, eating after dinner snacks and eating within 2 hours of sleeping.

Researchers who said that they would have these bad habits at bay could help lose weight and reduce BMI or body mass index and waist circumference.

The study looked at health insurance data for 59,717 Japanese with diabetes . These individuals had all submitted claims and had regular health check-ups. Each of these checkups looked at BMI, weight, waist circumference and blood biochemistry, urine tests and liver functions.

Each of the participants were given questionnaires to fill in their lifestyle, eating and sleeping habits. They were asked about their alcohol use and tobacco use. Each of these participants were classified as fast, normal or slow eaters.

Other eating habits of concern that were quizzed about eating included dinner within 2 hours of going to bed or eating snacks after dinner and skipping breakfast.


  1. They noted that 36.5% of the participants had at least one checkup over the 6 years of the study and 29.5% and 20% had at least 2-3 checkups during this period respectively.
  2. Of the participants 22,070 people were fast eaters while 33,455 ate at normal speed and 4192 were slow eaters.
  3. Health was better among slow eaters than among fast or normal eaters they noted. The rates of obesity were 29% and 42% lesser among normal speed eaters and slow eaters respectively compared to fast eaters.
  4. Waist circumference was also slightly lower between normal speed and slow eaters compared to fast eaters.
  5. Around 52% of the participants also changed their eating speed during the course of the study.
  6. Obesity was associated with bad eating habits such as snacking after dinner, going to bed within two hours of eating, alcohol etc.

Authors speculate that eating fast is linked to impaired glucose tolerance and development of insulin resistance. Both of these can raise the risk of diabetes and metabolic syndrome. These are associated closely to obesity.

They explain that fast eaters may take longer to feel full and may eat more than they need for satiation. On the other hand slow eaters take longer to feel full and thus the energy intake is lower.

Authors concludes, "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. "

Excess energy intake and low physical activity is similarly associated with obesity but was not accounted for in this study. Also being an observational study, this study fails to draw absolute conclusions accepted the authors of the study.