When does a calorie deficit become dangerous?
If you're like most people who want to lose weight, you want to lose it fast. So you may be tempted to make drastic changes in your diet to dramatically reduce the number of calories you consume. But what you may not know is that eating too few calories can actually backfire and sabotage your weight-loss efforts. It would make sense to stop eating when you are trying to lose weight, but it actually works in the opposite way.
Signs and Symptoms of Under-eating
If you’re not eating enough, an inadequate calorie intake could be the root cause of your health problems. Find out how to recognize the signs of under-eating. Below are the top signs and symptoms people who are chronically under-eating have. Read on to discover if you might simply need some more food to start feeling better today.
A super low-calorie diet, say of 1,000 calories per day or fewer, makes your body sense that it's starving. Appetite hormones kick in to prevent you from losing too much weight. Your metabolism slows, and your body holds onto fat. Any weight you lost initially has made your body smaller too. This means you naturally burn fewer calories at rest.
This is one of the most paradoxical symptoms of someone who is under-eating, and it often goes hand in hand with overtraining. For good reason, some are extremely frustrated that their weight isn’t changing; for some people their weight has actually been increasing since they dropped their food intake and started working out more. We’ve been trained to believe that the body is a machine, and we can input and output our calories in a way that will cause weight loss. So it’s understandable why some people would expect to see weight loss from a significant caloric deficit like that. But the fact is, they simply can’t lose the last 15 to 30 pounds no matter how little they eat. Why is this?
While a short-term, moderate caloric deficit can lead to sustainable weight loss (think 300 to 500 calories per day), much larger deficits induce changes in your body’s metabolism in order to keep your body in a homeostatic balance. Your body does not like major, drastic changes, and it will make modifications to your thyroid, adrenal, and sex hormones in order to reduce your overall caloric output. These changes include reducing active thyroid hormone, shutting down sex hormone production, and raising stress hormones like cortisol. Chronically elevated cortisol leads to both leptin and insulin resistance, a disastrous hormonal state that can keep body weight high.
These hormonal changes can lead to stalled weight loss and body fat retention, along with many other negative health effects that go beyond weight loss resistance. So, if you’ve been eating much less and exercising much more in a futile attempt to lose weight, consider whether this strategy has been working for you.
2. Severe Calorie Deficit Can Cause Fatigue and Nutrient Deficiencies
Regularly eating fewer calories than your body requires can cause fatigue and make it more challenging for you to meet your daily nutrient needs. For instance, calorie-restricted diets may not provide sufficient amounts of iron, folate or vitamin B12. This can lead to anemia and extreme fatigue.
In addition, the number of carbs you eat may play a role in fatigue. Some studies suggest that calorie-restricted diets with low amounts of carbs may cause feelings of fatigue in some individuals. However, other studies find that low-carb diets reduce fatigue. Therefore, this effect may depend on the individual.
Calorie-restricted diets may limit other nutrients too, including:
- Protein: Not eating enough protein-rich foods like meat, fish, dairy, beans, peas, lentils, nuts and seeds may cause muscle loss, hair thinning and brittle nails.
- Calcium: Not eating enough calcium-rich foods like dairy, leafy greens, calcium-set tofu and fortified milks may reduce bone strength and increase the risk of fractures.
- Biotin and thiamine: A low intake of whole grains, legumes, eggs, dairy, nuts and seeds may limit your intake of these two B vitamins, potentially resulting in muscle weakness, hair loss and scaly skin.
- Vitamin A: Not eating enough vitamin A-rich foods like organ meat, fish, dairy, leafy greens or orange-colored fruits and vegetables may weaken your immune system and lead to permanent eye damage.
- Magnesium: An insufficient intake of magnesium-rich whole grains, nuts and leafy greens may cause fatigue, migraines, muscle cramps and abnormal heart rhythms.
To prevent fatigue and nutrient deficiencies, avoid overly restricting your calories and ensure you eat a variety of whole, minimally processed foods.
3. Fertility and Immunity Problems
Infertility can also occur as a result of too few calories. Your body's production of sex hormones may reduce because of a too low-calorie intake. The American Journal of Endocrinology, Physiology and Metabolism published a study in 2015 showing that, in women, reductions in calories of 22 to 42 percent below what's needed to maintain their weight can lead to menstrual irregularities indicating problems with ovulation.
Scientists have known for a long time that low-calorie dieting and inadequate body fat can lead to infertility and amenorrhea in women. One of the most commonly seen manifestations of this problem is known as hypothalamic amenorrhea, which is hallmarked by menstrual irregularity or amenorrhea and low energy availability, with or without an eating disorder. Menstrual irregularity doesn’t necessarily mean a missed period; it can simply mean a woman is having an anovulatory cycle, meaning there is no egg released during the ovulatory period.
Also, catching colds regularly? Your low-calorie diet is to blame. Eating too little can negatively affect the immune system and stress out the body. When this happens, your body produces fewer lymphocytes, aka infection-fighting white blood cells, according to the Cleveland Clinic. Consequently, with lower lymphocyte levels, you run a greater risk of getting sick.
4. Mood disorders and depression can occur.
When you go long periods without eating, blood sugar tends to drop. If you don’t eat something to raise blood sugar, and it remains low, your ability to concentrate, be patient with others and mentally focus diminishes. Enter crankiness, which can easily be reversed by eating something.
Research in Current Neuropharmacology published in 2015 noted a connection between depressive symptoms, mood irregularities and calorie restriction. When you excessively restrict calories, your cognitive abilities are impaired and your mood can become negative. Your body perceives low-calorie intake as stress and responds accordingly. The result is a decrease in the output of a hormone known as leptin, which is associated with mood. Low leptin levels are connected to depression.
Have you ever heard the term “hangry” before? It refers to the state of anger and irritability resulting from being hungry. And even though it’s a made-up term, there’s actually scientific evidence for the existence of this volatile emotional state caused by inadequate food intake.
Lack of eating enough food can lead to hypoglycemia, or low blood sugar. Since the brain requires blood sugar to function optimally, when it starts to drop, one of the first cognitive processes that suffers is self-control. Your ability to exert self-control allows you to:
- Focus your attention
- Regulate your emotions
- Cope with stress
- Resist impulsivity
- Refrain from aggressive behavior
So, if you’re always on a short fuse, or your mood is constantly swinging between cheerful and irritable or anxious, make sure that you’re not severely under-eating before making any other significant changes to your diet and supplement or medication routine.
Some other signs of possible under-eating are:
constipation, hair loss, being unable to sleep, weak bones and joints, anemia, dizziness, low blood pressure and slow heart rate, always hungry etc.
The Bottom Line
When you lose weight, you want to lose fat and keep it off for the long-term. Shortcuts like eating just 1,000 calories per day may cause you to drop weight right away, but you'll only see your losses slow down and often stop. You'll lose lean muscle too, which only hurts you in the long run by lowering your metabolism and endangering your health.
Use a calculator, to track your daily calories and make sure you're getting enough nutrients and fuel to power your days, while not overconsuming so as to gain weight or stand in the way of weight loss.
16.08.2022