Learn to recognize the signs and symptoms your body uses to communicate to you that you are not eating enough.
Life’s demands—stress, illness, grief, hectic schedules—can significantly impact our appetite and how our bodies manage hunger. In the chaos, it’s easy to overlook how these factors might lead to insufficient eating. Similarly, many individuals striving for weight loss may unintentionally fall into patterns of under-eating or restrictive behaviors in their efforts to shed pounds.
Regardless of the cause, depriving your body of the essential nutrients it needs can have profound effects. Over time, consistent under-eating can disrupt your metabolism and throw your hormones off balance, creating issues that might not become apparent until much later.
Table of Contents
Let’s explore the clear signs that your body might be lacking essential nutrients like protein, carbohydrates, and fats—and discover how to boost your food intake with a well-balanced diet for optimal health.
1. Low Energy
If you’ve been feeling persistently exhausted for weeks, despite getting enough sleep, your diet might need a closer look. Under eating can leave your body without the fuel it needs, leading to sluggishness and low energy.
This is particularly common with low-carb diets, since starchy carbohydrates serve as the body’s primary quick-energy source. When they’re restricted, it’s no surprise that energy levels can suffer.
Consider both the quantity and variety of your meals. Are you including all the Foundational Five components, especially starchy carbohydrates? Are you eating when hunger signals arise and responding to your body’s needs?
2. Dizziness
Feeling dizzy can be one of the earliest physical signs that you’re not eating enough. When food intake is too low, blood sugar levels can drop, leading to lightheadedness or even fainting. If this keeps happening, and you’re unsure why, take a moment to evaluate your diet.
For a quick energy boost, try pairing carbohydrates with protein—options like a banana with almond butter, a handful of berries and nuts, or veggie sticks with hummus can help stabilize blood sugar and restore your energy.
That said, if dizziness continues despite nutritional adjustments, it’s best to check in with your doctor to rule out any underlying health concerns.
3. Poor Cognition and Productivity (i.e. Brain Fog)
Ever find yourself thinking, “Where did I put my keys?”? We all have those moments, but frequent brain fog could be your body’s way of signaling that it needs better nourishment—more food! While brain fog can stem from various health issues, it’s also a common sign of not eating enough throughout the day.
Skipping meals or delaying lunch for meetings and calls deprives your body of the fuel it needs to stay sharp. So if that afternoon slump hits hard and you realize you haven’t eaten, take it as your reminder to grab a meal or snack.
Prioritizing whole foods is key. Opt for a hearty salad packed with fresh veggies, sweet potatoes, avocado, grilled chicken, or another protein source, finished with a delicious dressing. Nutrient-rich foods containing B-vitamins, omega-3s, folate, and antioxidants can enhance brain function and support cognitive health. Say goodbye to brain fog and hello to clarity.
4. Hair Loss and Brittle Nails
This may come as a surprise to you, but if you’re not eating enough food or getting enough nutrients, the highest priority organs will take the lead in getting those nutrients. This includes your brain, heart, and lungs, rather than your hair, skin, and nails. Hair, skin, and nail health are closely tied to what you eat along with how many vitamins and minerals your body is absorbing.
It’s normal to lose between 50–100 strands of hair every day. If you’re losing more locks than usual and your nails seem to break easier, you may want to focus on nourishing your hair and nails from the inside out.
Start by eating foods that help produce more keratin, the protein that strengthens your hair and nails. Spinach, beans, oatmeal, salmon, eggs, and berries are all excellent sources of hair- and nail-loving nutrients. Protein, biotin, iron, vitamin B12, and omega-3 fatty acids, in particular, are the best nutrients for helping you maintain the thickness, luster, and growth of your crop.
5. Irritable Mood
Hanger is a real emotion! When you’re caught up in a busy day and skip breakfast, both your blood sugar and your mood can take a hit. Research suggests that low glucose levels can contribute to irritability, aggression, and even heightened stress. So, when your stomach is empty, frustration and mood swings might be the first signs that your body needs nourishment.
The best way to avoid hanger is to fuel up regularly with balanced meals and snacks. Keeping a consistent eating schedule helps stabilize blood sugar levels, ensuring steady energy and a positive mood throughout the day. When you start to feel those early hunger cues, don’t ignore them—listen to your body and grab a meal or snack to stay in control, energized, and feeling your best!
6. Feeling Chilly
Feeling cold all the time? Your body needs sufficient nourishment to maintain warmth while carrying out essential functions. Without enough food, thermogenesis—the process that helps generate body heat—may not operate efficiently. Studies suggest that those following restrictive diets often have lower body temperatures than individuals with balanced nutrition.
In cases of low body fat or being underweight, the body may compensate by growing fine, soft hair known as lanugo. This natural response helps trap heat when fat reserves aren’t sufficient for warmth. Lanugo is commonly seen in individuals with anorexia nervosa or those with extreme leanness.
Prioritizing a well-rounded diet with enough calories can support proper thermoregulation, keeping your body warm and functioning optimally. If you frequently feel chilled, it may be worth reassessing your food intake to ensure your body is getting the fuel it needs!
7. Constant Thirst
Making sure you eat enough is actually one way you can manage your hydration levels. Many of the electrolytes you get from food affect thirst. These include sodium, potassium, and magnesium. If you still feel thirsty after chugging down 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 aim for hydrating beverages such as caffeine-free teas, carbonated unsweetened seltzers, and good ‘ole water.
8. Amenorrhea
Amenorrhea, the absence of menstruation, can occur for various reasons. Factors such as pregnancy, dietary changes, stress, and certain medications—including contraception—can impact menstrual cycles. Additionally, health conditions like hypothyroidism and polycystic ovarian syndrome may disrupt hormone levels, affecting the regularity of periods.
Low body fat or being underweight (about 10% below a person’s normal weight, which varies individually) can also contribute to amenorrheal. Insufficient nutrition may hinder ovulation and cause hormonal imbalances, which is why women with disordered eating patterns or high-performing athletes often experience missed periods. In some cases, the body lacks the necessary nutrients to support essential functions.
The female athlete triad highlights the interconnected relationship between low energy intake, amenorrhea, and reduced bone density. This condition is especially prevalent in athletes striving to maintain a lean physique for sports such as figure skating, ballet, and gymnastics. Ensuring proper nutrition and balanced energy intake is crucial for overall health and menstrual well-being.