5 Signs You’re Eating Too Little for How Much You Work Out

Since the early 1970s the number of female athletes has grown by a whopping 560 percent among high school students and nearly one thousand percent among college students. This is fantastic news, of course: Athletics can lead to lifelong benefits in terms of girls’ (and women’s) health and self-esteem.

But in-step with this rise in participation, a syndrome called the female athlete triad has also become a growing problem. Characterized by an irregular menstrual cycle, low energy, and low bone density, the female athlete triad syndrome is most often caused by under-eating in relation to exercise.

As Health‘s contributing nutrition editor, I’ve written plenty on cravings, portion sizes, and ways to curb over eating. But in my work as a sports nutritionist, it’s not at all uncommon for me to tell one of my clients, “You aren’t eating enough.” I work with active women of all ages, from high school athletes to marathon-running women over 40 and everything in between, and I see undereating across the age spectrum.

While the triad (which can cause brittle bones, not to mention affect your performance) is most serious in female athletes who restrict their food because they have a true eating disorder, there are also plenty of active women who are unknowingly shorting themselves on their body’s energy needs.

Often there are telltale signs, but you may ignore them because you think you’re eating right. I’ve also seen women afraid to make eating changes due to fear of weight gain. Here are five indications you’re falling short of your needs, plus ways to strike a better balance.

You avoid eating post-workout

Many women I counsel avoid eating after they exercise because they think doing so cancels out their calorie burn. The truth is it’s not as simple as calories in and calories out. After a workout your body is primed to use nutrients for healing, so a healthy meal, like a veggie and avocado omelet with fruit, will provide the building blocks your cells need to recuperate from the wear and tear of exercise.

In fact, it’s really the healing, rather than the exercise itself, that makes you stronger, so not eating enough post-workout is a recipe for becoming weaker, which eventually leads to poor performance and injuries.

You’re tired all the time

There can be several causes of fatigue, including stress, a lack of sleep, and yep, under-eating.

Even at rest your body needs calories to support vital functions (your heart beating, lungs breathing, and circulation). A general rule of thumb is that if you’re relatively inactive you need about 10 calories for every pound of body weight, plus more for exercise. That means a 135 pound woman needs 1350 calories for just sitting there, not including the additional 400-500 for a one-hour cardio class, not to mention normal everyday activities like walking and doing laundry.

Yet I talk to many women who strive for no more than 1200 calories a day period, which may be as much as 35 percent less than what they really need. Even if you’re trying to lose weight, that’s too much of a disparity, which is why you’ll feel the effects, from low energy to irritability, moodiness, trouble concentrating, and sleepiness. Basically, it’s your body telling you, “Hey, you’re not giving me enough to do everything I need to do here.”

You aren’t having regular periods

This is a big red flag. While there may be other reasons for irregular periods, it’s often a sign that you aren’t nourished enough to maintain adequate hormone levels. You might think that you have to be underweight for this to happen, but it can happen even if your BMI is normal.

This imbalance can trigger a depletion of bone density, which ups the risk of fractures and osteoporosis. While osteoporosis is most common in older women, it can affect women in their 20s, 30s, and 40s. Unfortunately I’ve seen women suffer from serious bone fractures, including broken hips, early in life, due to long-term under-eating, and simply popping a calcium supplement isn’t enough.

You’re sick too often

Inadequate nutrition can lead to weakened immunity, and bottom line: drinking green juice, or taking vitamin C or zinc supplements can’t offset an overall lack of food. So if you seem to be one of those people that catches every cold or flu that comes along, take a serious look at your diet. Sometimes I’ll ask a female client if she would feel confident advising another active woman to eat exactly what she eats. A hesitation often helps people second guess just how restrictive they’ve become.

You’re afraid of food

As a nutritionist there are plenty of unhealthy foods I don’t want to put in my body. But there’s a difference between striving to eat clean and healthfully and becoming obsessive about food.

If you find yourself not wanting to eat when you feel hungry, avoiding social situations because you don’t want to give up control over your food, becoming more and more restrictive, or tying what and how much you eat to your self-esteem, talk to a professional. With my clients the primary goal is optimal health. Whether you’re training for an event, trying to slim down, or both, you should feel well, physically and emotionally, and have a healthy relationship with food and your body along the way. If that’s not how you feel you should know that it is possible, but you may need some support to get there.

Cynthia Sass, MPH, RD, is Health’s contributing nutrition editor, and privately counsels clients in New York, Los Angeles, and long distance. Cynthia is currently the sports nutrition consultant to the New York Rangers NHL team and the Tampa Bay Rays MLB team, and is board certified as a specialist in sports dietetics

This article originally appeared on Health.com

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