Ever wonder if you’re eating enough? Sharing 8 signs and symptoms to look out for that might mean you’re undereating.

We live in a diet-obsessed culture where the primary rhetoric is that we are eating too much and need to “cut back.” But because of this emphasis on restriction, many of us are actually undereating.

Unfortunately, undereating is glamorized in our society. People are praised for not eating that much and there’s morality wrapped up in it.

Have you ever heard of (or made) comments like: “Oh, you’re so good for not eating that dessert.” “Oh my gosh I wish I could only order an appetizer for dinner.” “You’re so disciplined for leaving half of your meal to take home.”

With all of this emphasis on eating less, no wonder so many people are not eating enough! If you’re undereating, I hope you can meet yourself with some compassion. None of this is your fault. You’ve been conditioned to believe that undereating is the healthy choice. That it’s the “good” choice. 

If you’ve ever wondered if you’re eating enough, read the signs you might be undereating below and remain curious about how these may or may not show up in your life.

8 Signs and Symptoms You May Experience When Undereating

1. Irritable Mood

If you’ve ever experienced “hanger”, you know all about an irritable mood. If you find yourself often feeling cranky, quick to snap, angry, or easily frustrated, your low blood sugar levels may be to blame.

When you don’t eat enough food or eat often enough, your blood sugar drops, which can elicit these feelings we’ve come to call “hanger.” Research supports this – one study found that greater levels of hunger were associated with greater feelings of anger, frustration, and lower pleasure.

2. Loss of menstrual cycle

If you don’t have a regular period, this can be a sign you’re not eating enough. Amenorrhea, the medical term for loss of menstruation, can happen when the body doesn’t have enough energy (from food) to support producing a period.

You see, the body does a wonderful job at physiologically compensating when it doesn’t receive enough fuel, in an effort to keep you alive. One of these compensatory mechanisms is conserving energy by shutting down “non-essential systems”, i.e. menstruation.

It’s also important to note that if you’re on a form of birth control and getting a regular period, that doesn’t mean you’re necessarily able to produce a period on your own, as the birth control hormones are essentially producing a period for you. Untreated amenorrhea can also lead to other health issues like infertility and osteoporosis. Struggling to get pregnant can also be a sign of undereating.

3. Low energy

If you’re tired all the time and struggle making it through the day, this may be a sign you’re not fueling your body adequately. Feeling low energy may mean you have low energy (aka calorie) intake.

Calories are quite literally units of energy. If you’re restricting your caloric intake, you’re restricting your energy intake.

Just as you wouldn’t expect a car to run for a while on little to no fuel, you can’t expect your body to run all day on little to no fuel. If you’re getting enough sleep and you’re still exhausted, chances are you’re just not eating enough.

If you aren’t sleeping well, this can also be a sign you’re not eating enough. It can be very hard to fall asleep and stay asleep when you’re hungry – research shows that restriction (in those with eating disorders) is associated with fragmented sleep and a reduction in deep sleep cycles.

4. Dizziness and Lightheadedness

Dizziness and/or lightheadedness is a symptom of physical hunger, which often shows up if you haven’t honored your hunger cues for a while. If you’re referring to the hunger and fullness scale, you might see these symptoms at a 1 or 2 on the scale, which is considered extreme or painful hunger.

If you’re noticing these symptoms, ask yourself is it possible this is a sign of physical hunger? Ask yourself how long has it been since I last ate something? You want to be aiming to eat at least every 3-4 hours to support stable blood sugar levels.

5. You feel cold often.

Got the chills? But like all the time? It’s one thing to feel chilly when it’s wintertime or you aren’t dressed properly for the temperature outside but if you’re often feeling chilly no matter what the weather and always reaching for a blanket, more layers, or a hot beverage, you might be under fueling.

Remember when we were talking about amenorrhea and how the body will make certain physiological changes to compensate for a lack of nutrition or energy intake? Well, this is one of those physiological mechanisms.

Regulating your body’s temperature requires energy in the form of glucose (found in carbohydrates). If you’re not taking in enough energy, your body is not going to waste energy on regulating its temperature.

6. You’re thinking about food all the time.

If you can’t stop thinking about food and feel like so much of your mental bandwidth is consumed by thoughts around eating, you’re probably not eating enough.

There’s actually a peptide in the brain called neuropeptide Y that is released when you don’t consume enough calories. Its role is to make you think about food, specifically carbohydrates, which are our body and brain’s primary source of fuel.

This is another one of those really smart survival mechanisms your body has in place to help you survive! If you’re not eating enough, your brain is going to remind you that you need to eat!

7. You’re losing hair.

Nutritional deficiencies – not getting enough protein, vitamins and minerals can lead to hair loss. Also, when you under eat, your body is going to conserve energy for the organs that matter the most like your heart and lungs, not your skin, nails or hair.

8. You’re constipated.

When you don’t eat enough food, you’re not going to have much bulk to produce a bowel movement. Not only that but in an effort to conserve energy, the body slows down your digestion.

If any of these symptoms resonated with you, and especially if multiple signs resonated, I suggest reaching out to an intuitive eating dietitian who can do a thorough nutrition assessment to make sure you are in fact eating enough. This is one of the most important things we assess for when we meet with new clients in our private practice.

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  1. Michelle

    Hi! With so many years of trying different diets (keto, vagan, low carbs, intermittent fasting……) I went to Perfect Body me. And they told me I didn’t eat enough and explained to me why. It make sense. So I’m on this meal plan it’s been since February, and they recommend me to eat between 1800 to 2200 calories per day. I never ate that before. So lost an ounce here and there, sometime gain with no reasons. Then oops lost another ounce. Two days ago, I ate ribs, living a life I call it. Weighing myself, and gained 3 pounds!!!! In no freaken time. Very discouraged. Can’t live a life. I’ve been exercising almost every day since January with a VR (very addicting). Now I’ve been told I don’t get enough sleep, I’m on the go all day from 5:30 am to 10 pm around and then I work out half an hour to 45 minutes then race to go to bed. Now I have to chose between working out or sleeping.

    • Hi Michelle – thanks for sharing. It sounds like you’re having a really hard time on this new plan. I hope you can find some peace soon. <3