Are You Actually Eating Enough? 8 Signs You Might Be Underfueling

Most of us live where convenience foods are at our beck and call. In fact, you can’t fill up your car with gas or shop at Home Depot without snacks on display. At the same time, diet culture is obsessed with telling us we’re eating too much. It’s confusing and contradictory. But here’s the irony: Many of us aren’t properly fueling ourselves—and we’re experiencing the physical signs of not eating enough.

Unfortunately, we’ve been jaded by weight loss articles, influencers on social media, coaches, etc. We’ve been told that in order to be healthy, we need to watch our calories, count our macros, and burn more than we consume. When it comes to a “clean eating” lifestyle, it’s a slippery slope. What can start as a passion for health can quickly turn into orthorexic habits. Often, the result of that is under-fueling. Today, we’re diving into the physical signs of not eating enough. While we all have different nutritional needs, a substantial breakfast is more than a freshly pressed green juice.

Featured image by Riley Blanks Reed.

How many calories do you need to eat in a day?

No surprise here: There’s no hard-and-fast rule. Person-to-person, the number of calories completely varies. Plus, no two days are the same. That said, calorie counts are usually based on your BMR or the energy (calories) needed for your body to perform normal systemic functions like nerve signaling or breathing. And that’s simply the bare minimum.

Conventional wisdom says the average woman shouldn’t eat fewer than 1,200 calories per day, and the average man shouldn’t eat fewer than 1,500. But these levels are essentially a calorie deficit. The bare minimum is not sustainable. And for many, it’s not healthy to be deficient in this category. Research shows that eating under 1,400 calories per day, for women, is not enough to support the menstrual cycle. Furthermore, a woman who is an avid exerciser, who is currently pregnant, etc. needs a much higher calorie intake.

Image by Jenn Rose Smith

The Power of Intuitive Eating

Rather than count calories—an exhaustive, impractical task—consider a more balanced approach. Hello, intuitive eating. This style of eating makes you the expert of your body and its hunger signals. It’s the opposite of a traditional diet. It doesn’t impose guidelines on what to avoid or when to eat. Instead, it teaches you that you are the best person (the only person!) to make those choices.

Rather than hop on the latest diet trend or mimic your favorite influencer’s style of eating, get back to the basics. Check in with your body. Without realizing it, your body is innately intuitive. It knows what it wants. Low energy levels? You could just be hungry. However, many of us struggle to stay in sync with our natural hunger signals, given all of the messages we read and hear. If you’re curious about intuitive eating, here’s where to start. 

Connecting With Your Natural Appetite

Between headlines spouting fad diets to social media celebs touting misinformation, it’s easy to get confused by what’s best for you and your body. Thus, it’s easy to mistrust your appetite. After all, we’ve been taught to disregard it. Read somewhere that fasting is important? Saw that eating after dark can cause weight gain? All of these messages are harmful, inaccurate, and stress-inducing. In essence, they encourage you to mistrust your hunger. If you’re not sure how much to eat, when to eat, and what to eat, you’re not alone. If you think you exhibit signs of not eating enough, it’s time to crowd out the unnecessary noise and reconnect with your body’s natural appetite.

Eating too few calories can cause your metabolism to slow down. Meaning, you won’t burn as much energy when you engage in physical activity. Your body requires energy for everything—thinking, breathing, exercising, sleeping, etc. When you deprive your body of the fuel it needs to burn calories, it will begin to store food and enter a sort of “survival mode.” So even when you exercise, your body will protect the fat it’s stored. This can cause a sluggish metabolism, chronic fatigue, food cravings, and more.

Image by Michelle Nash

8 Physical Signs You’re Not Eating Enough

Beyond the toxicity of diet culture, illnesses, grief, and the hustle and bustle of everyday life can take a toll on our appetites. These factors can affect how our bodies regulate hunger, which often leads to us not eating enough (or at the very least, showing the physical signs of not eating enough).

Whatever the cause, not eating enough food and depriving your body of important nutrients can manifest in ways that wreak havoc on your metabolism and hormones, both of which may take longer to notice if you’ve been consistently under-eating for your body type.

Let’s take a look at the not-so-subtle signs that your body may not be getting enough protein, carbohydrates, and fat, and what you can do to increase your food intake with a balanced diet.

Chronic Fatigue

Do you feel tired no matter how much you sleep? One of the earliest physical signs of not eating enough is having less energy than usual. Our bodies break down foods (mainly carbohydrate-rich foods) into glucose and then burn them for fuel. One of the side effects of not having enough fuel could be a dip in energy levels. Think of it this way: if you don’t get enough nutrition, you could end up feeling tired all the time. Intentionally or unintentionally, you can develop chronic fatigue. With chronic fatigue, you may begin to notice that even daily activities are tiring you out. Of course, you’ll notice less motivation at the gym, too. 

Fluctuating Glucose Levels

The physical signs of not eating enough can include hypoglycemia or low blood sugar levels. If you experience dizziness, sweating, or sugar cravings, you may want to consider a blood test to check your glucose levels.

Unhealthy Hair and Nails

Over time, one of the physical signs of not eating enough calories—or getting proper nutrients—is hair loss and brittle nails. Naturally, highest priority organs (brain, lungs, heart, etc.) will take the lead in getting those nutrients. Your hair, skin, and nails will get put on the back burner. That’s why you may notice your physical appearance takes a hit when your body doesn’t get the nutrients it needs. Hair, skin, and nail health are so closely tied to what you eat along with how many minerals, healthy fats, protein, and overall nutrients your body is absorbing.

Want more healthy hair tips? Check out our guide to biotin for hair health.

Poor Cognition (Brain Fog)

We all have moments of forgetfulness, but frequent brain fog could be your body’s way of telling you to check in with how well you’re nourishing yourself. Interrupting your normal meal times delays the energy your body needs to keep going. So if that 3 p.m. lull hits hard and you realize you haven’t had lunch, that’s your cue to head to the kitchen and make a hearty snack. Foods rich in B vitamins, omega-3 fatty acids, folate, and antioxidants can help boost brain function and prevent cognitive decline.

Mood Swings

When your glucose levels are too low, it can make it difficult for your body to produce enough serotonin. This can cause a cycle of mood swings and irritability. Add to that the dissatisfaction you feel about your body, and you’re stuck in an infinite loop. You may end up eating too little to feel nourished, quite literally making you hangry.

Irregular (Absent) Menstrual Cycle

This deserves a post in and of itself, but here’s the gist: Undereating can lead to amenorrhea. This is the scientific term for an absent menstrual cycle. Women may miss their periods for a variety of reasons, including pregnancy, changes in diet, and stress. Specific health conditions, like polycystic ovarian syndrome, can also affect your hormone levels.

However, amenorrhea is one of the most common physical signs of not eating enough (or having low body fat). Being underweight can stop ovulation and cause abnormal changes in your hormones, which is why some women with disordered eating habits or women who are high-performing athletes may often miss their periods. In some cases, their bodies also aren’t getting enough nutrients to carry out normal bodily functions.

Feeling Cold

If you constantly feel cold, not eating enough food could be the cause. Your body needs to burn a certain number of calories to create heat and maintain a healthy, comfortable body temperature. In fact, even mild calorie restriction has been shown to lower core body temperature.

Constant Thirst

Making sure you eat enough is one way you can manage your hydration levels. After all, many of the electrolytes you get in food affect thirst—sodium, potassium, and magnesium. If you still feel thirsty after chugging a glass of water, it’s a red flag that you may not be consuming enough calories. Sometimes, your body can also mistake thirst for hunger and misguide you away from the water bottle. Just remember to limit sugary energy and sports drinks, sodas, and fruit juices. Dehydration can also lead to constipation!

Image by Michelle Nash

How to Eat Enough Food

Stop Restricting Yourself

It’s not easy to stop restricting after a binge. After all, you’re feeling incredibly full and incredibly guilty for being so full. Know that this is a normal reaction. However, realize that by restricting one meal (or one day of eating), your body will require extra calories in the future. This, ultimately, can lead to a binge. And thus, the cycle starts all over again. Just remember: starvation mode is a big no.

Show Up For the Next Meal

Even if you ate past comfortable fullness earlier, make sure you show up for your next meal. Plan what you’re going to eat, at what time, and get someone in your support system to hold you accountable for that next meal, if you need it. The more you can create consistency in your meal times, the more your body will crave food every 3-4 hours.

Eat Every 3-4 Hours

Or have a snack! Instead of eating nothing for an entire day, thus setting yourself up for a binge at night, plan out your day’s food intake. That way, you establish a regular eating schedule. You should eat every few hours. And each day, you should be consuming an adequate amount of food for your personal needs. Not sure if you’re eating enough? Watch this. Consistently fueling your body every 3-4 hours keeps that extreme, binge-triggering hunger from taking over.

Recognize That Foods Are Not Defined as Good or Bad

One of the biggest lies spread by diet culture is that some foods are “good” and some are “bad.” Food groups, like carbs, are cast out as “bad” and diet culture tells you that you should consume them as little as possible. This automatically creates fear foods and/or temptation foods. When you are told you’re not allowed to have something you want, you start to become consumed by the thought of this food. This is a common reason why people binge on certain foods.

A big step toward freedom from obsessing about food is to realize that food is just food.

It has no morality. All foods have value, whether nutritionally or mentally, even if certain foods have less nutritional value than others (i.e., canola oil vs. coconut oil).

The less you restrict, the more you’re able to live in alignment with the natural rhythm of your mind-body connection.

Image by Michelle Nash

4 Signs You’re Actually Eating Enough

Eating enough is key to building a trusting relationship with your body. Ultimately, the indications you’re fueling enough are the opposite of the physical signs of not eating enough. The goal is to approach your hunger with compassion, curiosity, and a knowing that your body is giving you a sign to fuel it. If you don’t listen, your body will go into starvation protection, conserving calories, storing fat, and burning muscle for energy. These are four signs you’re actually eating enough.

You feel satisfied for roughly three hours

You may need to eat sooner, especially if your liver struggles to store glycogen. However, the goal is to feel hunger return about 3-4 hours after finishing your food.

You aren’t immediately craving an entire bag of chocolate chips

Meaning, you ate a proper, nourishing amount of carbs. Many sugar cravings stem from blood sugar imbalance. Don’t skimp on your complex carbs.

You feel satiated, content, and energized after your meal

You built a balanced plate with protein, carbs, healthy fats, and fiber while honoring your cravings.

You aren’t thinking about food all the time

If you’re constantly daydreaming about foods (particularly, any you’ve deemed “off limits”), you’re probably restricting the amount of food and the types of foods you’re eating.

This post was originally published on March 17, 2022, and has since been updated.