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A woman eating cereal while on the phone at a desk in front of a computer.

“I think we need to increase your calories.”

Whenever I make this suggestion to a client with a fat-loss goal, it’s often initially met with confusion and disbelief, followed by genuine curiosity, and finally, amazement when it actually works. I’ve even had a few clients who’ve successfully reached their body-composition benchmarks when consuming double their baseline calorie intake.

Although it’s certainly not the case for everyone, undereating is a surprisingly common issue for those struggling to achieve their desired weight or body composition. It’s also a frequent issue for those who are juggling family responsibilities, work demands, or on-the-go, overwhelming schedules.

Chronic calorie deprivation and too-low food intake — intentional or not — comes with a whole host of problems, including metabolic disruption and unwanted, unpleasant symptoms.

No matter what your health and fitness goal is, appropriate nourishment — from calorie-containing macronutrients (protein, fat, and carbohydrate), as well as micronutrients (vitamins and minerals) — is a non-negotiable. When your body is lacking in either, it usually sends some important warning signs.

If any of the issues outlined here sound familiar, it might be time to evaluate your intake to make sure you’re in a space of healthy nourishment instead of chronic deprivation.

1. You’re not sleeping.

Stable blood sugar overnight is one of the key components of restful sleep. When you’re not eating enough, however, the likelihood of blood sugar dropping too low increases. This can disrupt your sleep and cause you to toss and turn.

Frequent dips in blood sugar throughout the day and night can also add stress to the body and contribute to challenges in optimal adrenal function. As a result, one of the main stress hormones, cortisol, may get thrown off its regular rhythm.

Eating enough — and addressing meal timing — are some of the key components to healthy blood-sugar control, and therefore to restful and adequate sleep.

2. You’re not moving your bowels regularly.

Typically, this is one of the first signs of undereating. Optimally, you should be eliminating at least daily. If an insufficient amount of food is being consumed, it makes sense that not enough waste is produced to stay regular.

The physiology behind constipation does get a bit more complex, however. In times of undereating, our fiber intake takes a dip. Fiber is critical to bulk up stool and waste so that it passes more easily.

Additionally, under-eating calories can cause a decline in thyroid function as the body works to adjust and survive from the perceived lack of food. Since constipation is one common symptom of low thyroid hormones, it goes hand-in-hand with insufficient caloric intake.

This is worth exploring and addressing if you’re experiencing other common signs of slow thyroid function, including feeling cold, struggling to lose weight, or experiencing hair loss.

3. Your libido is gone.

Think about this from a survival standpoint: If there’s a perceived lack of food from insufficient intake, the body’s metabolic processes can take that as a sign that the times might not be safe or appropriate for reproduction. Hormone levels can shift, and sex drive can take a compensatory nosedive.

For the men I’ve worked with who were undereating, it’s common to see free testosterone levels drop. The stress of not eating enough can raise levels of certain binding proteins in the blood that act as sponges and make testosterone less available for use. As a result, libido tanks; when this happens, men often feel apathetic and physically weaker as well.

In women, disrupted or missing menstrual cycles are a common occurrence if calorie intake is insufficient.

Even when reproduction is not the goal, a healthy libido is a sign of in-sync hormones and optimal functioning. If yours is missing, be sure to evaluate your food intake to determine if it may be a contributing factor.

4. You’re cranky.

With chronic under-nourishment, the changes in stress hormones coupled with underlying hunger can lead to some significant changes in behavior. Low resilience to stress, feeling short-tempered, and struggling with foggy thinking can result.

The brain is responsible for up to one-fifth of our caloric expenditure, so a caloric deficit is sure to affect cognition and outlook. If your calorie deficit is significant enough to cause changes in your disposition or relationships, it may be time to adjust the plan.

5. You’re dragging in your workouts.

When it comes to exercise, I always say, “You can only progress as hard as you recover.” Exercise in and of itself is a stressor on the body: It adds respiratory demand, challenges the nervous system, and causes micro-tears in muscle. These stressors are all good provided your body has what it needs to heal and come back stronger over time.

Along with sleep, adequate nourishment through amino acids from proteins, anti-inflammatory omega-3 fats, and antioxidants from colorful produce all play a role in supporting optimal exercise recovery. When intake is low, the raw materials needed to recover are lacking.

As a result, exercise without the right recovery can move our health and fitness in the wrong direction, resulting in extended soreness, plateaus or decreases in strength and stamina, and excessive fatigue.

What to Do

If you’re noticing signs signs of undereating above, the idea of increasing calories might initially feel daunting. However, the key to long-term, sustainable results is to work with your body, not against it.

Your metabolism’s primary goal is survival. With any perceived threat to survival, underlying metabolic compensatory mechanisms will activate in an attempt to help protect you — it is these very same mechanisms that might contribute to unchanging or stubborn body composition. In fact, to the body, the lack of fat loss may be a “win” that is helping you survive.

The most efficient path is be to enlist the help of a qualified coach to ensure that your intake is sufficient from both a quantity and quality standpoint. Working to include nutrient-dense foods in the right balance, along with core foundational supplementation, can provide the life-giving, energy-boosting nourishment needed to help your body feel its best. While it’s rarely a quick fix, it’s worth it in the long run.

Contact us here if you’re a Life Time member and ready to connect with a coach to help determine the best approach for you.

Keep the conversation going.

Leave a comment, ask a question, or see what others are talking about in the Life Time Training Facebook group.

samantha-mckinney-life-time-training-registered-dietician
Samantha McKinney, RD, CPT

Samantha McKinney has been a dietitian, trainer and coach for over 10 years. At first, her interests and experience were in a highly clinical setting in the medical field, which ended up laying a strong foundation for understanding metabolism as her true passion evolved: wellness and prevention. She hasn’t looked back since and has had the honor of supporting Life Time’s members and nutrition programs in various roles since 2011.

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