Undereating may cause weight gain for some people, but even if it doesn't, it's important not to eat so little that it adversely affects your health. From constipation to immune dysfunction, not eating enough can lead to a host of health issues.
Calories and Your Health
But if your calorie intake dips too low, says Lummus, your body could go into starvation mode. "Your body will start to store fat because it thinks it is not going to get anything," says Lummus. "You will be at a point where your body is kind of at a standstill."
If you take in fewer calories than needed, you will lose weight ( 1 ). Restricting intake to fewer than 1,000 calories daily can slow down your metabolic rate and lead to fatigue since you're not taking in enough calories to support the basic functions that keep you alive.
You've gained muscle.
And here's an often overlooked fact: Muscle tissue is more dense than fat tissue. So as you gain more muscle and lose fat, you change your overall body composition, which can result in a higher weight, but a smaller figure and better health.
Muscle is denser than fat, and as it is more compact within your body, as you gain muscle mass, you end up looking thinner, no matter your physical weight. So, if you've been doing a lot of strength training lately, it's likely this is the reason that you're looking fantastic but not dropping those numbers.
“When you start exercising, your muscles start gobbling up fuel called glycogen,” says Krista Scott-Dixon, Ph. D., Director, Headspace Adjustment Bureau, Precision Nutrition. Since glycogen stores water, you could gain up to 10 pounds in water weight alone, says Scott-Dixon.
You're holding onto water weight.
It's as simple as that really, unless you're incredibly small and in active you should and will lose weight on 1000 calories unless of course you're chronically stressed or really suck at counting calories.
Hypoglycaemia can occur in people who are very low weight, not eating enough calories and who have also depleted their glucose stores in their muscles and liver. If they cannot breakdown muscle fast enough to restore glucose in their blood, or if they don't have enough muscle left their heart may stop beating.
You can't lose weight on 1200 calories a day because you're no longer in a calorie deficit. Your body has adapted to what it's been doing and plateaued. If you start your diet with a 500 calorie deficit per day, your body adapts to this in various way so that over time your energy requirements are reduced.
As a general rule, people need a minimum of 1,200 calories daily to stay healthy. People who have a strenuous fitness routine or perform many daily activities need more calories. If you have reduced your calorie intake below 1,200 calories a day, you could be hurting your body in addition to your weight-loss plans.
Eating too few calories can cause a major decrease in metabolism. Although a calorie deficit is needed for weight loss, it can be counterproductive for your calorie intake to drop too low.
A 1,500-calorie diet fits the needs of many people who want to lose fat and improve health. Like any healthy diet it should include mostly whole, unprocessed foods. Reducing excess calories and using some of the simple tips in this article can help you succeed in your weight loss journey.
When you eat too few calories, e.g., a 900-calorie diet, it interrupts your metabolism. As stated above, your body thinks that you are starving, and thus, it signifies to your appetite hormones that something is wrong. They slow down your metabolism, which means that you will no longer be burning calories.
A 1,200-calorie diet is much too low for most people and can result in negative side effects like dizziness, extreme hunger, nausea, micronutrient deficiencies, fatigue, headaches, and gallstones ( 23 ). Furthermore, a 1,200-calorie diet can set you up for failure if long-term weight loss is your goal.
Weight loss
You could be malnourished if: you unintentionally lose 5 to 10% of your body weight within 3 to 6 months. your body mass index (BMI) is under 18.5 (although a person with a BMI under 20 could also be at risk) – use the BMI calculator to work out your BMI.
Feeling cold: According to a study published in the journal Aging, calorie restriction reduces your core body temperature, therefore you feel cold. Lethargy: On a starvation diet, you would not likely be eating enough, which will leave you constantly exhausted.
Research shows that being underweight is MORE harmful to your body than being overweight. If you're not eating enough energy, you're literally starving yourself. If you're severely under eating, your body functions will eventually start to shut down and it will likely lead to serious health complications.
You've Gained Muscle Mass
If you're exercising regularly and doing a mix of cardio and strength training, it's very likely your body composition (ratio of muscle to fat) is changing for the better. If you're gaining muscle while losing fat, the scale may not show any weight change.
Weight gain
Exercising too much without resting enough in between can lead to low testosterone levels and high levels of cortisol, the stress hormone. These hormonal changes are often associated with loss of muscle tissue, weight gain, and excess belly fat.
If you're a man, woman weighing over 164 pounds or a female who regularly exercises and you aren't losing weight eating 1,200 to 1,500 calories daily, it may be time to see a doctor. Hormone imbalances – such as underactive thyroid – can decrease your body's metabolism and inhibit or prevent weight loss from occurring.
Most people begin to see weight loss results in 3-4 weeks. If you're not losing weight in a calorie deficit you may need to adjust your stress levels, diet, and sleep patterns. Other reasons for weight gain during a calorie deficit are hormonal changes, aging, and other health conditions.