This study analyzed health insurance data from 59,717 diabetic people in Japan, who all submitted claims and had regular checkups between 2008 and 2013. Waist circumference, weight, BMI, blood chemistry, urine tests and liver functions were included in each of the participant’s individual check ups. Questionnaires in regards to their lifestyle, sleeping and eating habits, as well as tobacco and alcohol use were filled out by each participant. Each individual participant was either classed as a normal, slow, or fast eater. Additional eating habits that were of concern the participants were quizzed about included eating snacks after dinner, skipping breakfast, and eating within 2 hours before going to bed.
Results showed that 36.5% of participants had at least 1 check up over the 6 year period with 29.5 having 2 and 20% having 3. 22,070 participants were fast eaters, 33,455 ate at normal rates, and 4192 participants were slow eaters. Health was observed to be better among the slower eaters. Obesity rates were decreased 29% among normal speed and 42% among slow eaters as compared to fast eaters. Waist circumference was highest among fast eaters. Approximately 52% of the participants changed their eating speeds during the period of this study. Obesity was associated with bad eating habits such as eating within 2 hours of bedtime, alcohol consumption, snacking after dinner, etc.
It is speculated by the researchers that eating fast is linked to impaired glucose tolerance and development of insulin resistance, both of which increase the risk of diabetes and metabolic syndrome that are associated very closely to obesity. Fast eaters take longer to feel full and eat more than needed for satiation. Changes in eating habits can affect obesity, waist circumference, and BMI. Interventions geared at decreasing eating speed may be effective in preventing obesity and decreasing the health risks associated.
Excess energy intake and low physical activity is also associated with obesity but not taken into account for this observational study, limitations making it unable to draw absolute conclusions.