What times someone eats during the day and how frequently may play a role in having a healthy weight and heart.According to an American Heart Association scientific statement published Wednesday, eating breakfast, avoiding late-night eating and mindful meal-planning are associated with a lower risk of heart disease, blood vessel diseases and stroke.
However, current research doesn’t dictate the best approach.
“There’s conflicting evidence about meal frequency,” said Marie-Pierre St-Onge, Ph.D., writing group chair and associate professor of nutritional medicine at Columbia University in New York City. She said studies have shown the benefit of intermittent fasting and eating smaller, frequent meals throughout the day.
Fasting every other day helped people lose weight in the short-term, but its long-term effects haven’t been studied, according to the statement. And there’s no guarantee that such fasting can be sustained.
“I can see scenarios where intermittent fasting can backfire,” said Penny Kris-Etherton, Ph.D., R.D., a statement co-author and nutrition professor at Penn State University. For example, people who fast one day could eat more than twice as much the next day, she said. She also questioned what would happen if someone who fasted regularly for lengthy periods of time – weeks or even months – then started eating regularly every day.
Because there’s not a lot of information about how people could practice intermittent fasting, Kris-Etherton cautioned against using it as a weight loss or weight management strategy until further information is available.
Eating frequent meals has also been found to reduce the risk of cardiovascular disease risk factors, says St-Onge. One study of men showed that those who ate more than four times a day had a lower risk of obesity than those eating three or fewer times a day. But other studies have found the opposite, with a greater risk of weight gain over time in those reporting eating more frequently.
Frequent meals may also be impractical, said St-Onge.
“If you eat five to six meals, it’s hard to create a meal that’s so small that you aren’t overeating at each of the sessions,” she said.
Eating dinner or snacking late at night had a detrimental effect on weight and heart health, according to the statement.
This may be due to how late night eating affects the body’s internal clock, which responds to circadian rhythms when metabolizing food and absorbing nutrients, according to the statement. Circadian rhythms also guide sleep and wake cycles. Emerging evidence shows that the liver and other organs have their own clocks that also affect metabolism, which may also explain why late night snacks and meals are detrimental.
For example, animal studies suggest that eating during times usually spent sleeping led to weight gain, insulin resistance and inflammation, St-Onge said, but that hasn’t been shown in humans.
Several studies have shown the benefit of eating breakfast every morning: it may help reduce the amount people eat the rest of the day, and lower the risk of high cholesterol and blood pressure. Some research reported that breakfast-skippers are more likely to be obese, have diabetes and not get recommended nutrients according to studies.
But breakfast studies also have recently come under fire when media reports showed Kellogg and General Mills, the two largest U.S. cereal manufacturers according to Hoovers, funded some of the research. This could have skewed positive results about the benefit of breakfast. Further research is needed to understand how breakfast could help people control their weight.
Proving definitive benefits of breakfast will require more direct head-to-head studies, as most of the research is based on weaker, observational studies, St-Onge said.
“It makes sense that eating more earlier during the day and less at night is more healthful, but the studies aren’t available,” she said.
Regardless of timing, statement authors continue to emphasize the benefit of a diet that includes fruits, vegetables, whole grains, low-fat dairy products, poultry and fish, and limits red meat, salt and sugary drinks and foods.
Having the right mindset about eating and planning ahead can also affect weight and heart health, said St-Onge. She recommends paying close attention to hunger cues.
“All or none” thinking can lead to binge eating excessive calories, she said. A research participant told St-Onge he could not eat one piece of pizza without consuming the entire pie.
“You don’t have to eat like there’s no tomorrow,” she said. “Have a little pleasure today…and tomorrow!”
Despite evidence about meal timing, the bottom line to healthy eating is calories, Kris-Etherton said.
You can’t eat excessive calories for breakfast, or eat five high-calorie meals a day and expect to lose weight, she said.