Are You Eating Enough? And The Symptoms of Negative Energy Imbalance
On the surface, we all know what food is. When we begin to dig a little deeper, however, we discover that it’s much more complex. Food is the source of all the raw materials we need to build and repair our tissues, organs, and systems. Food is information, in the form of nutrients, that tells our cells what they should or shouldn’t be doing. And food is fuel; it’s the potential pool of energy we give our bodies to work with.
Food affects our health and performance, arguably more than any other lifestyle choice we make. Dietary habits and food preferences can vary widely from one athlete to another. And given that our genealogy, biology, physiology, and psychology are all very different, that’s perfectly understandable. Despite the rise (and inevitable fall) of any given dietary trend, it’s important to realize that there is no such thing as a one-size-fits-all formula for eating "right."
Compared to our hunting and gathering ancestors, most modern societies enjoy relatively easy access to an abundant supply of food. As a result, some of us end up struggling with health and performance issues that stem from eating too much and moving too little. But many face an entirely different type of obstacle--a negative energy imbalance caused by eating too little and moving too much.
While carrying too much or too little body weight is the most obvious indication of a positive or negative energy imbalance, addressing and overcoming this obstacle is complex and involves more than just gaining or losing a few pounds.
Finding Your Balance
Energy balance plays a key role in determining something that’s much more important than how much you weigh; it determines the strength or weakness of your underlying cellular health. When your energy balance is negative, everything from your immunity and digestion to your metabolism, mindset, and mood can all be impaired.
When faced with an ongoing energy deficit, for example, the thyroid and adrenal glands send out certain hormones that will slow the body’s metabolic processes down. Reducing the rate of its energy output is one of the primary tactics the body uses to protect and restore itself. In fact, a chronic energy deficit is one of the primary reasons why men and women who follow calorie restriction diets often end up gaining--instead of losing--weight.
Are You Eating Enough?
It’s not enough to rely on what the scale says or how your clothes fit. What matters most is how you feel. Do you have even, consistent energy throughout the day, or do you experience troublesome high’s and low’s? Chronic under-eating leaves us more susceptible to suffering from hypoglycemia (low blood sugar). Low blood sugar can cause symptoms that range from hunger, shakiness, anxiety, and dizziness to sweating, weakness, confusion, and mood swings.
Have you ever heard the term “hangry” before?
It’s urban slang used to describe the feelings of anger and irritability that come from being really, really hungry. Even though the term is made up, there’s some hard-core, scientific evidence supporting the validity of this volatile emotional state caused by an insufficient food intake. The brain depends on a steady supply of glucose to function optimally. When blood sugar levels fall too low, one of the first cognitive processes to suffer is self-control. A lack of self-control can make paying attention, regulating emotions, coping with stress, and refraining from impulsive actions very difficult.
The body can also express its need for more energy in a number of other ways.
1. Are you often constipated?
Chronic under-eating may be the culprit as an ongoing energy deficit can negatively impact the health of the thyroid gland, leading to a reduction in the amount of hormones it produces. Constipation is a very common symptom of hypothyroidism (low thyroid function) since thyroid hormone controls and directs peristalsis (the wave-like muscular contractions in the intestines that keep the digestive process working smoothly and efficiently). When thyroid hormone levels drop, the entire elimination process slows causing chronic constipation.
2. Do you sleep well?
Insomnia and other sleep-related disturbances are a common complaint among athletes. But poor sleep is particularly problematic for those who are running on empty. As the body’s blood sugar level drops overnight, the liver must release some of its glycogen stores in order to keep it steady and continue fueling all its basic functions. If your energy balance is consistently negative, your liver won’t have the glycogen stores it requires to keep your blood sugar stable.
Low blood sugar will trigger the release of the stress hormones cortisol and adrenaline which turn on gluconeogenesis--the production of new glucose from stored energy. If these stress hormones get high enough, they can literally wake you up in the middle of the night.
3. Do you frequently feel cold?
An energy deficit can lower your body temperature. Without an adequate supply of energy, the body can’t support thermogenesis--the natural production of body heat. A low insulin level can also lead to reduced thermogenesis and a low body temperature so women who follow a very low-carbohydrate diet may frequently feel cold, too.
4. Have you experienced unexplained hair loss?
Hair loss is one of the first signs of nutritional deficiency that can be exacerbated by the hormonal changes that develop from an energy insufficiency. These changes include a drop in sex hormones like progesterone, testosterone, and estrogen. Hair loss is also a very common symptom of hypothyroidism (an over-active thyroid).
5. Do you have lots of headaches?
Not all athletes experience hunger in the same way. Instead of a growling stomach, their first hunger cue often comes in the form of a headache. Hunger headaches happen when the amount of energy being consumed isn’t enough to meet the body’s needs. The resulting drop in blood sugar that triggers a headache can also cause shakiness, irritability, and fatigue. The stress hormones that are released when the body is low on energy can also cause a headache. The same stress hormones will also increase if you are dehydrated or suffering from a lack of sleep.
How Much Should You be Eating?
Determining how many calories your body needs on a daily basis for optimal health, performance, and recovery can be a little tricky. There are a number of different variables to consider. How much of what kind of food you eat and the type and intensity of physical activity you do are both very important.
While it’s almost impossible to determine the exact number of calories your body requires, there are some ways to get a rough estimate of your daily minimum. If you enjoy math, you might want to take a crack at the Harris-Benedict Equation. It offers a reasonable estimate of your basal metabolic rate or BMR, the minimum number of calories your body needs to perform its basic, life-sustaining functions.
BMR = 655.1 + (4.35 × weight in pounds) + (4.7 × height in inches) - (4.7 × age)
Doing the math results in a caloric estimate that has about a 10% margin of error, which might not seem like much. But if your estimated BMR is 1700 calories a day, your actual need will lie somewhere between 1530 and 1870. Multiplied on a daily, weekly, and monthly basis, it’s easy to see why relying on this formula can lead to an energy imbalance. And remember, this equation does not take your activity level or health status into account.
An easier way to get an idea of the minimum number of calories you should be eating is to simply multiply your ideal body weight by 10. Again, it’s important to note that this quick estimate applies only to a sedentary body; it doesn’t take into account the additional energy demands of any physical activity.
While these formulas can provide you with a place to start, monitoring your body for clues that come in the form of hunger, fatigue, weight loss, digestive difficulties, fitness declines, or poor recovery will ultimately serve as a much more reliable indicator of your body’s essential energy needs.