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Amazing Benefits of Overnight Oats, According to Science

There are multiple reasons why this is such a beloved breakfast.
FACT CHECKED BY Olivia Tarantino

If you had to suss out the next big foodie trend, you probably wouldn't visit a hospital cafeteria for gourmet inspiration. But that's exactly the origin of uber-trendy overnight oats, an idea born of a Swiss doctor back in 1900 who was looking for an easy way to serve up the numerous benefits of oatmeal to his hospital patients.

The original meal, muesli, roughly translates to "mash-up" and that's what overnight oats are: a mix of raw oats, soaked overnight in water, milk, or yogurt, and then served, uncooked, with fruits and nuts. Foodies swoon over the creamy, pudding-like consistency—and we're swooning over the health and weight loss benefits. Grab a spoon and a mason jar, and consider all healthy reasons to make overnight oats a breakfast (or anytime!) staple. To get started, check out these 51 Healthy Overnight Oats Recipes for Weight Loss.

You'll feel fuller and burn more fat

apple cinnamon overnight oats

Raw oats are one of the best sources of resistant starch. This weight loss-friendly starch passes through your small intestine undigested until it reaches the colon. Here, the resistant starch acts as a food source for the good bacteria that live in your gut, helping to keep your microbial balance healthy by providing a better ratio of "good" to "bad" gut bacteria. The bacteria ferment the starch into digestive acids shown to suppress the appetite and speed up calorie-burning. In fact, swapping just 5 percent of daily carbohydrates for resistant starch could boost the metabolism by 23 percent, according to a Nutrition & Metabolism study.

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You'll avoid a poor food choice

woman looking at unhealthy breakfast in pastry case

"I was so stressed out that I grabbed something incredibly healthy for breakfast!" Said no one, ever. When time (and your temper) runs short, chances are you'll go for the donuts. And that's one more reason to love overnight oats: There's no room for error, as you're forced to plan ahead. People who rely on planning, not willpower, consistently make healthier food choices, research suggests. A study in the International Journal of Behavioral Nutrition and Physical Activity showed that meal preppers are at a lower risk of being overweight or obese than those who didn't have ready-to-eat food.

You'll absorb more nutrients

overnight oats blueberries

Wallow in a hot bubble bath and you can almost feel the negative energy seep from your pores. That's kind of what happens when you prep overnight oats. The process of soaking the whole grains in an acid mixture helps break down phytic acid, an antinutrient that interferes with digestive enzymes and inhibits mineral absorption. Cooking is one way to damage control a phytic faux-pas, but soaking with a touch of lemon juice or apple cider vinegar may be even better at easing digestibility.

You'll get a bigger breakfast

overnight oats

It's the amount of food that fills us up, not the calories, according to research in The American Journal of Clinical Nutrition. In this study, men consumed 12 percent less of a milkshake that was pumped with air to double in size than when served the same, equal-calorie shake without the added volume. That's the beauty of overnight oats, which—unlike their cooked counterparts that tend to shrivel in the heat—swell in their slumber and quadruple in volume. So when it looks and feels like you're eating more (but are really eating the same number of calories), you'll feel even more full!

You'll improve your heart health

Happy doctor making a heart shape and smiling

Oat bran has a heart-healthy reputation as a cholesterol fighter. Oat fiber called beta-glucan has been shown to reduce cholesterol levels by 5 to 10 percent, according to a study in the Journal of Nutrition and Metabolism. You'll need to eat two servings of regular oatmeal daily to reap the benefits. But just one bowl of overnight oats may be equally, if not more effective. That's because the traditional preparation calls for lemon juice; and the added vitamin C can boost oatmeal's ability to lower cholesterol, according to a study in the Journal of Nutrition.

You'll enjoy carbs again

woman eating oatmeal happy

Chances are you'll really enjoy overnight oats. And that's a good thing. Because the degree to which we enjoy a meal—or not—has huge implications on the amount of nutrients we absorb, research suggests. Thai women fed a traditional Thai dish absorbed twice as much iron than a group of Swedish women fed the same meal, which they reported not enjoying. And when the two groups ate traditional Swedish fare, the Swedes absorbed 50 percent more iron than the Thai women who didn't care for the meal, according to a study a University of Colorado Law School report cites. The more enjoyable your oaty experience, the more zinc, copper, magnesium, biotin, and B vitamins you'll absorb.

And for more, check out When It Comes to Oatmeal, This Is the Healthiest Way to Eat It.