Raise your hand if you’ve ever glanced at the clock after powering through your to-do list only to realize you can barely remember when you last had a snack. Or you skipped breakfast because your well-intentioned plans to meal prep did not, well, go according to plan. No matter the reason, sometimes skipping meals is just a fact of life. And although it seems innocuous, experts are pretty emphatic about eating regularly because of the effects skipping meals can have on your body and mind. That said, you may have heard that skipping meals in the form of intermittent fasting (IF) can benefit your health or lead to weight loss. Although IF has gained popularity for those reasons, there's not much in the way of reliable or definitive evidence that it's more useful for weight loss than traditional caloric restriction or that it's particularly useful for health or longevity purposes.
Here’s exactly what goes down (two experts used the term “hangry,” if that’s any indication).
As a general rule, aim to eat every few hours.
Although the specific timing will vary from person to person, there are various reasons why it's a good idea to eat something every three to four hours. “Eating regularly throughout the day…prevents dips in your energy, keeps you alert and focused," and helps prevent eating past the point of fullness, says Brigitte Zeitlin, M.P.H., R.D., C.D.N., founder of the New York-based BZ Nutrition. It’s not like if you don't eat often enough on one day, all your systems will immediately go haywire. But your body will react to the dearth of fuel in various ways.
If you skip a meal, you'll likely start to feel sluggish and be unable to focus.
“The main fuel for your brain is glucose, which you get from eating foods—predominantly carb-rich ones,” Rachele Pojednic, Ph.D., assistant professor in the nutrition department at Simmons College and professor at the Harvard Extension School, tells SELF. Complex carbohydrates, like fruits, vegetables, and whole grains, are the most nutritious sources of glucose because they take a longer time to digest than refined carbs (plus they’re often loaded with other beneficial nutrients). Without a frequent carb supply, your blood sugar can dip too low, leaving you feeling sluggish, irritated, and like you can’t concentrate, says Zeitlin.
Then the physiological symptoms start kicking in.
While you might not be able to concentrate on tasks like answering emails, you sure will be able to focus on food. When you don’t eat often enough, “the feeling that you need to have something to eat takes over,” Lauren Harris-Pincus, M.S., R.D.N., owner of Nutrition Starring You, tells SELF, adding that craving food and not having it means it's prime hanger time.
“Hormones like ghrelin, which is appetite-inducing, and leptin, which is appetite-suppressing, will change to indicate you’re hungry,” says Pojednic. When you don’t satiate that hunger, you might experience feel yourself get shaky or even a bit sweaty in response.
All this might make you reach for sweet, carb-y stuff, which will only help temporarily.
“When people are super hungry, they tend to go for the carbs and sweets because those will raise their blood sugar,” says Harris-Pincus. The thing is, carbo-loading without nutrients like fat and protein to temper the rise in glucose can make your blood sugar spike, then dip, which is not ideal. It also just won't keep full or satisfied for as long, which means your problem is solved only temporarily.
And beyond that, when you wait till you're absolutely ravenous to eat, you're also more likely to eat past the point of fullness or even comfort. “You are likely to overeat to make up for the lack of calories you took in throughout the day,” says Zeitlin. “That can cause nausea, constipation, bloating, and exhaustion.” Overeating usually happens because you're taking food in way too quickly and ignoring your body's satiety cues, says Pojednic.
And over time you'll feel fatigued and may experience other long-lasting effects.
When you don't eat often enough, you may not get enough protein, which is important for muscle growth, bone health, your immune system, and more. When you're low on protein for long enough your overall energy will take a hit, which will making working out and building more muscle (or even keeping what you already have) pretty tough. “Skipping meals doesn’t only affect the nutrients you consume, but your ability to exercise and lead a healthy life,” says Harris-Pincus.
Although determining how often you need to eat takes some experimentation and is an individual thing, it's worth figuring out what works for you. A trustworthy registered dietitian can help, as can learning about intuitive eating to get more in tune with your body's hunger and fullness cues.