The Most Common Causes of a Slow Metabolism

Spread the love

Some people can eat whatever they want and they won’t gain fat while others can just take a look at fast food or sweets and they gain pounds. This is due to a particular part of the genetics of humans, but also due to a “broken” metabolism. Those of you who can eat whatever they want usually have good genes and an extremely well-functioning metabolism. This ensures among other things that nutrients are processed better and faster.

But it is also up to each one of us, to take care of our metabolism, so it can work properly. Relevant factors include water absorption, protein and fat intake, and enough sleep.

Diets have great influence on the metabolism. Thus, an intense diet (great calorie deficit) performed for very long periods of time, slows down your metabolism. So even if relatively small amounts of energy is supplied to the body (in terms of body type, size and weight), a damaged metabolism ensures that the goal of body weight reduction can not be achieved. The body goes into energy preservation mode as a self protection measure. This reaction goes back to the time when food was not in abundance around us.

Some theories suggest also that it is always difficult to lose weight after one gains a significant amount of weight. When a drastic calorie deficit is applied for longer time, the organism goes into energy preservation mode and it’s harder to lose weight.

Now of course some will say that professionals always rely on drastic diets when they do a bulk phase and then decrease their weight radically again. That certainly may be true. The difference, however, is that professionals often use enhancement drugs (eg steroids, doping agents) that keep the thyroid gland producing and hormone levels high even while dieting, thus making the fat loss process possible. So do not be fooled by the standards, they are definitely not equal for all.

Slow metabolism can be associated with bad diet unmistakeable, but sometimes other things also play a role in how fast your metabolism is. Since you already know you have a slow metabolism, you next need to find out why is it that way. Is it something you do or just your genetics ?

Here are some common causes for a slow metabolism.

1. Very Low ammount of nutrients

A low calorie diet, which is carried out over a long period will considerably slow down the metabolism. As already mentioned, this takes place as a protective reaction of the body. Usually during a very low calorie diet, the hands and feet become cold as a result of the very low energy supply. The body draws all its blood to the body where is needed the most.

A big mistake by athletes that want to reach their final goal quickly, is starting a too intense diet right away. The body just does not have the time to get used to the drastically reduced calorie intake, and therefore a rapid metabolism shutdown begins.

This is why you never start with drastic changes in your diet. But rather decrease your calories by 10-15% of your total. That’s about 300-500 calories per day. After about 2-3 weeks see how your body reacts and cut another 300-500 calories. Some experts suggest taking small diet breaks that last a few days, so you can allow the hormone called leptin to increase and bring your metabolism back on track. This is also how intermittent fasting works.

2. Very low fluid intake

Another reason for slow metabolism is often the low fluid consumption. Remember, the human body is 65% water. Even without any sport activities you will lose approximately 2.5 liters a day through sweating, breathing or urinating. Digestion of food also requires water.

Besides digestion, water is also involved in the transport of nutrients, enzymes and hormones in the blood. Only 2% loss of water will make a person lose a great deal of their strength.

That is why we recommend a minimum consumption of 3 liters of fluids per day. This value varies according to height, weight and activity, respectively. A good indicator that you are properly hydrated is the color of your urine, which should be almost colorless or transparent.

3. You don’t eat enough fats

Yes, even when dieting, it is important for the body to have fats. While we need some carbohydrates while dieting, fats and proteins are absolutely essential for our body. Athletes make a big mistake when they cut the fats almost to zero while dieting.

Make sure you know, what kind of fats you consume. Make unsaturated fats primary, and consume just a small amount of saturated fats. Stay away from trans fats at all causes.

Unsaturated fats are essential because they can not be produced by the body, but they are needed to build body cells. You can find them in all sorts of fish, nuts or olive oil.

Saturated fatty acids, however, the body can produce by itself and therefore they are only required in small quantities. They are however needed for the production of anabolic hormones in the body as well as absorption of vitamins such as A, E, D and K.  Saturated fatty acids are found in products such as butter, milk, beef steak and chicken legs.

An optimal dosage of essential fatty acids is 0.8 to 1 gram per kilogram per day.

4. You don’t eat enough protein

Fats are important, but protein is even more important, why?

Simply speaking, proteins are the building materials which your body needs to repair damaged cell structures. This means athletes should always be careful to have enough protein in the diet itself. Because only then the body can repair the damage made to fibers by intense exercise. In addition,  a large portion of energy is used just to decompose the protein you eat. This “thermogenic effect of food” short TEF is highest in protein compared to fat and carbohydrates. Therefore high protein diets are better when it comes to cutting body fat.

In combination with intense exercise you need to consume 1-2g of protein per lb of weight.

5. The last possible cause of a slow metabolism, lack of sleep.

Sufficient sleep is important for a fit mind but also for a fit body. Although it is possible to get away with little sleep sometimes, in a matter of days your body will return the “favor”.

It is very important to get a good night’s sleep of 8-9 hours, because only then a full regeneration processes take place, and without regeneration no construction is possible.

Today, there are enough research results about the fact that sleep is essential for a well functioning metabolism. Too little sleep increases the cortisol levels and consequently leads to muscle breakdown.

Many people say that 4-6 hours is just enough for a good night’s rest and everything is a matter of habit. But in the long run I’m sure they will feel that the lack of sleep negatively impacts performance and physical well-being.

So a good nigh rest of about 8 hours and even a nap during the day can make wonders for concentration, well-being and sports performance.

The reasons for a slow metabolism can be many, but there are a few that can be controlled. Try to find the mistakes and correct them. A “broken” metabolism can be annoying but is not a reason to throw in the towel. If you stick to the basics mentioned here, you will surely make a long-term success and decrease the number of problems with a slow metabolism.


Lane, MA. / Baer, DJ. / Rumpler, WV. / Weindruch, R. / Ingram, DK. / Tilmont, EM. / Cutler, RG. / Roth, GS. (1996) Calorie restriction in rhesus monkeys Lowers body temperature, consistent with a postulated anti-aging mechanism in rodents. In: Proceedings of the National Academy of Sciences of the United States of America: 1996; 93 (9); S.4159-4164. URL:
Benzinger, TH (1969): Heat regulation: homeostasis of central temperature in man. In: Physiological Reviews: 1696; 49 (4); S.671-759. URL:
Benzinger, TH. (1959): On physical heat regulation and the sense of temperature in man. In: Proceedings of the National Academy of Sciences of the United States of America: 1959; 45 (4); S. 645-659. URL:
Judelson et al. (2007): Hydration and muscular performance: does fluid balance affect, strength, power and high-intensity endurance? In: Sports Medicine. URL:
Judelson et al. (2007): Effect of hydration state on strength, power, and resistance exercise performance. In: Medicine & Science in Sports & Exercise. URL: