How eating a diverse diet can cause weight gain.
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For decades, nutrition experts have said that eating a wide variety of foods is key to controlling weight and staying healthy.
But that seemingly common-sense mandate might not always add up to the healthiest diet, according to a new scientific advisory from the American Heart Association.
Indeed, heeding the advice to eat a more diverse diet could lead to increased calorie consumption, weight gain and a more unhealthy diet overall.
The new advisory points out that there are many ways to define a varied diet, and some of them aren’t so healthy.
For example, some people might think that instead of eating an array of mostly unprocessed whole foods, a “varied diet” means eating different types of meats, refined grains and foods that are high in sodium or sugar, says lead author Marcia C. de Oliveira Otto, assistant professor of epidemiology, human genetics and environmental sciences at the University of Texas Health Science Center at Houston.
“The mantra of ‘everything in moderation’ — even refined grains, sugary foods and processed foods — has left consumers confused,” says Amy Keating, a nutritionist at Consumer Reports. “And I think this new advisory shows that taking that ‘variety’ message too far is not ideal.”
Food options and pounds
Several of the studies examined in the AHA advisory found that more often than not, people who ate a large number of different types of foods ate more processed meats, sugar-sweetened beverages, refined grains and salty snacks.
“Even in diets that included a wide variety of healthy foods, we didn’t see the benefits — like lower risk of diabetes and obesity — we expected, possibly because those diets also included high quantities of unhealthy foods,” Otto says.
But the potential downsides of diet diversity go beyond eating some unhealthy foods. Studies have shown that having too many choices leads to eating more food — and consequently, more calories.
For instance, in one study cited in the AHA review, overweight people who were offered a variety of foods for their snacks ate 25 percent more snack servings per week than people who were told they could eat any amount of one favorite snack.
The same goes for meals — having more types of dishes on the table could lead to overconsumption. “When people are exposed to different tastes in one meal, the feeling of being full is delayed and they eat more,” Otto says.
“It remains a good idea to eat a variety of foods, but they have to be healthy foods,” Otto says. That way, you’ll have a better chance of taking in enough of all the essential nutrients you need.
So go ahead and stock your kitchen with a number of different items from healthy food groups — fruits and vegetables, lean proteins, nuts, beans and unprocessed whole grains.
And, yes, you can still have the occasional cookie. But this is where it pays to limit variety. Instead of filling the pantry with a slew of different treats, keep just one favorite on hand. With few unhealthy choices hanging around, you’ll be less likely to overindulge.
“The goal is to aim for controlled, mindful diversity in your diet,” Otto says. “That means that even if there are some unhealthy foods in the mix, the scale needs to tip toward the healthy.”