Patrice Wendling

November 22, 2017

ANAHEIM, CA — Skipping breakfast, unhealthy diets, and overeating are known to contribute to weight gain, but new research suggests the simple act of eating too fast may also promote metabolic syndrome and obesity.[1]

After 5 years of follow-up of 1083 Japanese men and women who rated their eating speed during a yearly health exam, new-onset metabolic syndrome was diagnosed in 11.6% of fast eaters, 6.5% of normal eaters, and 2.3% of slow eaters (P<0.05 for both between-group comparisons).

Fast eaters also saw greater gains in waist circumference (4.0 vs 1.5 vs 0.25 cm; P=0.007) and overall body weight (5.3 vs 0.23 vs –1.56 kg; P<0.001), according to data reported here at the American Heart Association 2017 Scientific Sessions.

"If you feel your own eating speed is faster than other people in daily life, you may have a risk factor for metabolic syndrome," study author Dr Takayuki Yamaji (Miyoshi Central Hospital, Hiroshima, Japan) told | Medscape Cardiology.

This is not the first time the association has been observed, with another study, among 8941 Japanese adults reporting that fast eating correlated with a 30% risk-adjusted increase in metabolic syndrome compared with slower eating.[2]

Several studies have also shown that fast eating contributes to the new onset of obesity, in part because it prompts overeating.

"If you chew your food many times, you spend more time at meals, you're more likely to feel full," Yamaji said. "It takes about 20 minutes for signals from your stomach indicating that you are full to reach your brain."

Eating fast also causes acute glucose fluctuations, he said. As a result, oxidative stress is increased, which leads to increased insulin resistance, decreased insulin secretion, and can further lead to hyperglycemia.

At baseline, fast eaters were significantly more likely than normal or slow eaters to have higher levels of fasting blood glucose (104.0 vs 100.8 vs 98.3 mg/dL) and lower levels of HDL cholesterol (56.8 vs 60.8 vs 62.6 mg/dL), though triglycerides and blood pressure were similar.

Fast eaters were less likely than normal or slow eaters to report drinking alcohol everyday (32.2% vs 40.3% vs 40.7%) but also significantly more likely to eat dinner 2 hours before sleeping at least three times a week (38.2% vs 28.9% vs 25.9%), snack after dinner three or more times a week (23.5% vs 16.4% vs 14%), and have gained weight in the past year (48.9% vs 28.6% vs 27.1%).

After adjustment for multiple confounders, however, risk of new-onset metabolic syndrome remained significantly higher among fast eaters than normal eaters (odds ratio [OR] 1.89; 95% CI 1.21–2.98, P=0.006) or slow eaters (OR 5.49; 95% CI 1.30–23.3, P=0.003).

Among the individual components of the metabolic syndrome, fast eaters fared significantly worse than the other two groups for waist circumference (P=0.002) and blood sugar (P=0.04), but not for triglycerides, HDL levels, or blood pressure.

In multivariate analysis, current smoking and getting sufficient sleep every day—neither of which differed significantly between groups at baseline—were also independent predictors of metabolic syndrome.

Dr Scott Grundy (University of Texas Southwestern, Dallas), who was not involved with the study, said "This is not a subject that I've seen in the literature, but it’s worth consideration and future research. It's an interesting idea."

He also noted that it seems reasonable that people who eat too fast may also eat too much.

Yamaji suggests this can be particularly perilous as Americans tuck into the Thanksgiving holiday meal, where the sentiment is often whoever eats the fastest gets the most.

"Festive meals tend to have more calories. Please eat slowly and be careful not to eat too much," he cautioned.

The investigators reported no relevant financial relationships.

Follow Patrice Wendling on Twitter: @pwendl. For more from | Medscape Cardiology, follow us on Twitter and Facebook.


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