Losing weight and saving money aren’t all that different. While the latter requires spending less, the former requires consuming fewer calories. But what some people don’t realize is that cutting too many calories can actually stall weight loss, says Lisa Young, PhD, RD, a nutritionist and adjunct professor of nutrition at New York University.
Plus, it’s tough to stick to a super low-calorie diet. Not eating enough for breakfast, for example, will leave you famished, making it harder to skip that cinnamon bun in your morning meeting or lead you to overeat at lunch.
While calorie needs differ based on activity level, goals, and gender, most women should consume at least 1,200 to 1,500 calories daily, according to the National Institutes of Health. Once you dip below that number, it becomes difficult for the body to perform basic biological functions that keep us healthy. Not sure if you’re hitting that number—or the number that’s right for you? Here are a few signs that you may not be eating enough to see the scale tip in your favor.

Can’t get through your afternoon to-do list because you’re getting distracted dreaming about dinner? You’re probably not eating enough. Reaching for healthy snacks between meals can help to increase your daily caloric intake and keep you focused on things other than food. To stave off hunger and overeating, Young suggests pairing a protein-packed food with something rich in fiber. Cottage cheese or a small handful of nuts with a piece of fruit fits that nutritional bill (or try one of these salty snacks that can actually help you lose weight).

Skipping breakfast (or subsiding on a breakfast of black coffee) and starving yourself until lunch is not the key to weight loss. You definitely need to watch calories to lose weight, but psychologically you’ll constantly feel deprived if you cut out too much, Young says. And that’s what makes you more likely to binge or break a diet later on.
Related: How To Prevent A Binge Before It Starts
If you’re accustomed to eating fairly regularly, following a diet plan that only allows for three small meals a day will leave you constantly craving more. To stay on track with your weight loss goals, Young suggests having three meals and two small snacks a day, sticking with healthy sources of calories, like fresh produce, lean meats, healthy fats, and whole grains. (Hit the reset button—and burn fat like crazy with The Body Clock Diet!)

If you’re losing weight at a healthy pace, you shouldn’t notice major changes in your cycle, Young says. However, if you’re not consuming enough calories, it can cause your period to become irregular. It may even stop it from coming altogether—likely because the body doesn’t have enough fat to produce the sex hormones that trigger the menstrual cycle, research suggests.
There are many reasons for a late period other than pregnancy. Here are 7:

Your brain runs on the glucose found in your blood, and the glucose in your blood comes from the carbohydrates you eat. Limit your calories and carbs too much, and your brain will become energy-starved. Feeling shaky, dizzy, or light-headed—or getting otherwise unexplainable headaches—are signs you’re not eating enough, and your blood sugar has dropped too low. Simply adding more calories and carbs to your diet should stop your head from pounding—and help the pounds come off more rapidly, too.

If the idea of a spin class leaves you dreaming of your pillow, you may not be eating enough, Young says. When you’re not consuming enough energy, you’re bound to feel tired all the time, which is a major motivation-suck.

If you’ve ever waited too long before eating dinner, you know what “hangry” means—that unpleasant combination of being so hungry you get angry. The same thing happens when you’re restricting calories too severely, Young says.
In fact, some research suggests acts of self-control (like adhering to a strict diet) are associated with angrier behavior. If you’re trying to lose weight, you want to limit calories just enough to slim down, not change your mood. (These 6 tricks to combat hunger and lose weight can help!)
Related: 10 Simple Ways To Improve Your Mood Fast

Limiting yourself to a tiny salad for dinner will leave you feeling empty and wanting more. But if you fill the rest of your plate with whole grains, healthy fats, and a lean protein, you’ll be far less likely to crave dessert. Plus, you’ll load up on the nutrients your body needs, Young says. Portion control is not about tiny portions. It’s about eating larger portions of healthy foods (like these 20 low-calories salads that won’t leave you hungry), and smaller portions of the less healthy stuff, she adds.