Have you ever been on an extreme diet where you lose weight rather quickly at first, but over time it become harder to lose weight and it become very difficult to stick with your diet because the hunger pangs intensify?
Many popular weight-loss diets call for very low calories: 800 to 1,200 per day or less for women and 1,500 to 1,800 per day or less for men. Diets with a calorie deficit of more than 30 percent below maintenance level can be considered as extreme diets. These diets are tempting because they can produce quick weight loss in the beginning.
However, in the long run, many people failed to lose fat by doing extreme diets. Many experts don’t recommend extreme diet as a way to lose fat and so do I. There are at least 10 reasons why you should avoid extreme diet if you want to lose fat permanently.
1. Extreme diet slows down your BMR
When you reduce your food intake and lose weight, your Basal Metabolic Rate (BMR) or the amount of calories you burn at rest will decline. This situation is called “Adaptive Thermogenesis” (TA).
One famous study that proves the existence of TA is the Minnesota Starvation Experiment by Ancel Keys and his colleagues in 1944-1945. In the study, 32 healthy male volunteers underwent 6 months of semistarvation. From month 3 to 6, their BMR fell by 39%.
That’s why when you’re on a diet, you lose weight rather easy at first. But then it will become harder to lose weight over time, because your BMR will decrease. With similar activity level, you’ll burn fewer fat than before.
2. Extreme diet decreases your NEAT
Non-Exercise Activity Thermogenesis (NEAT) is the calorie burned for all of your physical activities except sports-like exercise. It’s the energy expanded for daily living activity such as walking, working, typing, shopping, etc.
Extreme diet can make you lethargic. Your activities could be decreased, because you fatigue easier. When your activities decrease, your NEAT will be decreased. When your NEAT decreases, you burn fewer fat than before.
3. Extreme diet decreases your energy and work capacity
Some people do better than others when training under less-than-ideal conditions. But as a general rule, extreme diets are not conducive to good workouts or an active lifestyle. One of the first signs of undernutrition is loss of energy and the ability to sustain intense training.
Without enough fuel coming in, you’ll fatigue faster, your strength will suffer, your performance will plummet, and your results will be compromised. To maximize your fat burning and build your best body, you must be able to train hard. If you’re hardly eating, you can hardly train.
4. Extreme diet may increase the risk of muscle loss
When your body is starving, it looks for ways to conserve energy. Since muscle burns calories and muscle is extra weight you have to lug around, getting rid of it is an easy way for your body to burn less. Lean people who already have low body fat are more likely to lose muscle than overweight people, but it can happen to anyone.
Dieting without resistance training can cause 30 to 50 percent of your weight loss to come from lean tissue. The risk of muscle loss is higher if your protein intake is too low. Even when you’re lifting weights and eating enough protein, if your diet is too severe, some of the lost weight can still come from muscle.
5. Extreme diet increases hunger and cravings
The first thing you notice during a calorie shortage is the hunger. You should expect a little hunger when you’re in a calorie deficit, but with extreme diet you become ravenous. It’s almost impossible to stay on a diet when you’re battling voracious hunger and all you can think about is food.
More than a dozen hormones influence how hungry or full you feel. The urge to eat can also be psychological or environmental. You tend to want what you can’t have, so if your diet is too low in calories or it sets too many rules about what you can’t eat, the feeling of deprivation triggers cravings and binges. It’s worse when you’re surrounded by temptations and eating cues all day long.
6. Extreme diet reduces thyroid hormones
Thyroid is a small gland in your neck. It produces at least two hormones that regulate your metabolism, i.e. triiodothyronine (T3) and thyroxine (T4). Hence, thyroid hormones affect your capacity to burn fat.
Doing extreme diet could reduce your T3 and T4 hormones. Since both hormones serve to keep or speed up your metabolism, reduction in both means reduction in your capacity to burn fat.
7. Extreme diet decreases leptin hormone
Leptin is a hormone made primarily in your fat cells. Its function is to tell your brain whether or not you have enough energy stored in your fat. If your brain senses that you have enough energy, then you will burn fat at a normal rate.
However, if your food intake or body fat stores go down, your leptin levels drop. If your leptin is low, your brain will sense starvation. It will then trigger “starvation responses” in your body. Starvation responses is a set of adaptive mechanisms that kick in when your body senses starvation, to protect you against starvation.
It works by telling your body to stop burning so many calories (decreasing your metabolism), start conserving energy, and increase the drive to find food. Extreme diet could make your leptin level drop and trigger starvation responses, thus reducing your capacity to burn fat.
8. Extreme diet increases cortisol
Extreme diet could cause or increase stress. When you’re on a diet, you try to resist temptation and the feeling of being hungry. You also need to monitor your calorie intake every day. These activities elicit negative emotion or stress.
When you’re stressed, your cortisol level will increase. Cortisol is a hormone secreted by your adrenal glands in response to mental and physical stress. It reduces your body’s ability to build muscle. Hence, extreme dieting could make you difficult to build muscle and burn fat.
9. Extreme diet decreases testosterone
Testosterone also takes a hit when you cut calories too much. This makes perfect sense from an evolutionary point of view because if you can’t even feed yourself, you’re in no condition to bear and feed offspring, are you?
In a study from the Journal of Applied Physiology, US Army Rangers who were in a calorie deficit of about 1,200 calories per day under conditions of sustained workload, inadequate sleep, and thermal strain experienced a drop in testosterone that approached castration levels.
Most research says that a conservative calorie cut of 20 percent below maintenance level won’t affect testosterone. As the calorie cuts get more aggressive and your body gets leaner and leaner, low testosterone becomes more of a concern.
10. Extreme diet increases the chance of weight regain
Almost everyone loses weight at the beginning, but later on, when the weight loss slows down and the hunger pangs intensify, most people give up. Even worse, they end their diet with a binge.
That’s bad news, because it can prime your body to regain weight more easily and leave you fatter than when you started. Eventually, you get sucked in by the newest fad diet, and the yo-yo diet cycle starts all over again.
This up-and-down pattern of weight loss and regain is known as weight cycling, and many people suffer through this for years or even their entire lifetime. Not only is it unhealthy, but with each cycle your metabolism becomes less efficient and you may actually get fatter more easily while eating less food than before.
The Solution: Moderate Diet
The odds of losing fat in the long run with extreme diet are stacked against you. Biologically, extreme diet will make your body more difficult to burn fat and build muscle. Psychologically, it’s almost impossible to stay long on an extreme diet. When it becomes harder to lose weight and the hunger pangs intensify, you’ll most likely give up on your diet.
This doesn’t mean you shouldn’t go on a diet at all. If you want to lose fat, you must create a calorie deficit. A calorie deficit means that the number of calories you consume is less than the number of calories you burn. This means you have to go on a diet, but your diet should be moderate, not extreme.
I recommend a calorie deficit between 15 and 30 percent below your maintenance level. For example, if you choose a calorie deficit of 20 percent and you’re an average female with a maintenance level of 2,100 calories per day, a 20 percent deficit is a 420-calorie reduction, which gives you a goal of 1,680 calories per day. If you’re an average male and your maintenance level is 2,800 calories per day, a 20 percent deficit is 2,240 calories per day.
However, this is not a rigid prescription. There are some situations where a larger deficit makes sense. For example, a severely obese person with potentially life-threatening conditions may need a larger deficit to lose fat quickly. But for most people, the moderate diet is the safest and healthiest way to lose fat.
To become successful in your fat loss efforts, you have to pick a plan that you can stick with long-term. A moderate diet is easier to follow and stick with over the long haul. In the process, you’ll also develop new healthy eating habits. Once the fat is off, you can gradually increase your calories to maintenance level, and you already have new habits that will keep you lean for life. If you want to lose fat permanently, this is the way to go.
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