Eating slower may help with weight loss

Dining with fork and knife

Whenever we focus on losing weight or preventing weight gain, we tend to only focus on what we eat. Ketogenic diets, plant-based diets, low-fat diets: the conversation typically stops with food. How quickly we eat is little more than a fleeting afterthought. Based on a recent study in BMJ Open, we may want to pay a little more attention to how fast we eat. Before you tell everyone to count how many times they chew their food or start handing out stopwatches at the dinner table—let’s break down the study’s findings.

Researchers looked at almost 60,000 people with diabetes in Japan who had health check-ups from 2008 to 2013. The Japanese Ministry of Health, Labor, and Welfare introduced the health check-up program to identify risk factors for weight gain in response to an increasing prevalence of people with excess weight. During these check-ups, screeners asked people questions about their eating and sleeping habits. The screeners focused on how fast people ate—categorizing people as fast, normal, or slow eaters. They also assessed the frequencies of skipping breakfast, snacking after dinner and eating two hours before sleeping.

The researchers found that slow eaters were significantly skinnier than the faster eaters. In fact, they found that slow eaters were 42 percent less likely to suffer from obesity than fast eaters. Similarly, regular speed eaters were 29 percent less likely to be overweight. Significantly more women were slow eaters compared to men. Overall, 22,070 people ate like The Flash, 33,455 people ate at an average speed and 4,192 ate mindfully and slowly.

If you are concerned about gaining weight ... you not only need to think about what you eat but also how you eat.

The researchers also found that eating snacks after dinner and eating within two hours of sleeping at least three times per week were both associated with a higher body mass index (BMI). Interestingly, the researchers did not find an association between skipping breakfast and weight gain—I still advocate for eating breakfast.

The findings aren’t surprising to me. Prior studies have linked eating too fast with blood sugar issues and weight gain. Although no one has clearly explained how eating fast leads to weight gain, the connection is likely due to the possibility that fast eating creates more of an opportunity to take in more calories before your body recognizes fullness. Even competitive eaters recommend trying to maintain a fast pace and avoid slowing down.

It’s also not surprising to me that people who ate late at night or had after-dinner snacks had higher weights compared to those who didn’t. Due to our circadian rhythms, the human body isn’t geared towards eating late at night—we aren’t nocturnal creatures.

Ultimately the authors of the study 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.”

Sometimes eating fast is necessary. Trust me, as a resident physician, I’ve seen people finish meals while running to patients’ rooms for a code blue cardiac arrest. This study shows that you shouldn’t make eating fast a habit.

Also, based on this study, I don’t recommend eating late at night or snacking after dinner.

If you are concerned about gaining weight, or if you’re trying to lose weight, this study shows that you not only need to think about what you eat but also how you eat.

author details Edwin McDonald

Edwin McDonald IV, MD

Edwin K. McDonald IV, MD, is dedicated to improving the health of individuals and communities through nutrition education.

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