The faster you eat, the more kilos you gain?

Are you wondering why your waistline is expanding? Don't watch what you eat; watch how you eat.

People who eat slowly are less likely to become obese or develop metabolic syndrome, a cluster of heart disease, diabetes and stroke risk factors, according to preliminary research presented at the American Heart Association's Scientific Sessions 2017, a premier global exchange of the latest advances in cardiovascular science for researchers and clinicians.

Metabolic syndrome occurs when someone has any of three risk factors that include abdominal obesity, high fasting blood sugar, high blood pressure, high triglycerides and/or low HDL cholesterol, said Japanese researchers.

The researchers evaluated 642 men and 441 women, average age 51.2 years, who did not have metabolic syndrome in 2008. They divided the participants into three groups depending on how they described their usual eating speed: slow, normal or fast.

After five years, the researchers found that fast eaters were more likely (11.6 percent) to have developed metabolic syndrome than normal eaters (6.5 percent) or slow eaters (2.3 percent).

Faster eating speed was associated with more weight gain, higher blood glucose and larger waistline.

Author Takayuki Yamaji from Hiroshima University said that eating more slowly may be a crucial lifestyle change to help prevent metabolic syndrome.

"When people eat fast they tend not to feel full and are more likely to overeat. Eating fast causes bigger glucose fluctuation, which can lead to insulin resistance. We also believe our research would apply to a U.S. population," he added.