What Is The 13-Day Metabolism Diet? What You Need To Know

Also known as the “Royal Danish Hospital diet, “the Royal Danish Hospital Diet,” and “the Copenhagen Diet,” the 13-Day Metabolism Diet is the latest fad diet making its rounds on the Internet.

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The diet not only helps you drop a significant amount of weight in a short amount of time, but it claims to change your body’s metabolism in less than two weeks. Furthermore, it alleges that the metabolism changes stay with you long after the diet is over, making it easier to lose weight in the future.

Also Read: How To Lose Weight Fast: 10 Smart Ways (Guaranteed To Work)

You’ll certainly lose weight following the 13-day plan (up to 22 pounds, it claims), but not because of a magical combination of foods; rather, as a result of its severe caloric restrictions. As for the metabolism boost? Well, let’s just say we’re skeptical.

Here, we take a closer look at the 13-day metabolism diet and see whether the plan lives up to the hype.

If you are looking for more diet guide like this, Check out FoodiesWiki.Com. William Smith has a bunch of detailed recipes and diet guide in his site.

What Is The 13-Day Diet?

Although the 13-day diet plan lasts for less than two weeks, it is very strict, and can be very difficult to follow. The diet spells out exactly what you will eat for the duration of the program. The exact specifics of the 13-day diet will vary based on who’s recommending it, but the many variations are clearly related. Here are some of the restrictions you’re likely to find on the various versions of the 13-day diet.

  • No chewing gum
  • No alcohol
  • No cooking oil
  • No salad dressing
  • No sweeteners like sugar and honey
  • No foods not listed on the metabolism diet plan

The diet does not allow any substitutions. It recommends drinking plenty of water. Some iterations allow for the use of salt and pepper; others disallow salt.

On the 13-day diet, what you will eat for each meal as strictly prescribed. To give you an idea of the sort of meals this diet includes, here’s a popular version of the diet presented on LiveLean.

The 13-Day Diet Plan:


  • Breakfast: Black coffee (always without sugar and milk)
  • Lunch: 2 boiled eggs and cooked spinach (where no amount is specified on a food, you can have as much as you want)
  • Dinner: Lean grilled steak


  • Breakfast: Black coffee with buttered whole wheat bread
  • Lunch: Ham (200g)
  • Dinner: Grilled lean steak, green salad (made with only lettuce and cucumber) and quality fruit


  • Breakfast: Black coffee and buttered whole wheat bread
  • Lunch: 2 boiled eggs, tomato salad and green beans
  • Dinner: 1 slice of ham and green salad (only cucumber and lettuce)


  • Breakfast: Black coffee and buttered whole wheat bread
  • Lunch: Cooked or raw carrots, with cheese
  • Dinner: Fruit salad (any fruits of your choice) and natural (plain) yogurt


  • Breakfast: Carrot (cooked or raw) with lemon and black coffee
  • Lunch: Grilled white fish with raw tomato
  • Dinner: Grilled steak & green salad


  • Breakfast: Black coffee and buttered wholewheat bread
  • Lunch: 200g Grilled skinned chicken
  • Dinner: 2 boiled eggs with carrots


  • Breakfast: Lemon tea
  • Lunch: Grilled steak & fruit
  • Dinner: Anything (even if its not on this list)!!!


  • Breakfast: Black coffee with as much SUGAR as you like
  • Lunch: 2 boiled eggs, cooked spinach
  • Dinner: 200g Grilled steak


  • Breakfast: Black coffee and buttered wholewheat bread
  • Lunch: Grilled steak and green salad
  • Dinner: 200g Ham

DAY 10

  • Breakfast: Black coffee and buttered wholewheat bread
  • Lunch: 2 boiled eggs, tomato salad and green beans
  • Dinner: Ham and green salad (only cucumber & lettuce)

DAY 11

  • Breakfast: Black coffee and buttered wholewheat bread
  • Lunch: Cooked or raw carrots, with cheese
  • Dinner: Fruit salad and natural yogurt

DAY 12 & 13

  • Breakfast: Black coffee and buttered wholewheat bread
  • Lunch: Tomato and grilled skinned chicken
  • Dinner: 2 boiled eggs with carrots

Is The 13-Day Diet Healthy?

The 13-day diet makes some truly bold claims, with little scientific evidence to back them up. There are a number of red flags associated with this extreme weight-loss method. First, such a massive weight loss in a short period of time seems unreasonable and unsustainable. According to the Mayo Clinic, a typical recommendation for how much weight you should safely aim to lose per week is 1 to 2 pounds. Any more than this, and you’ll losing muscle in addition to fat, and it can make it more likely that you’ll regain the weight later (which can cause serious health problems of its own).

Second, the foods listed on the diet are extremely restrictive, making it difficult to get the full range of vitamins and nutrients that your body needs to function properly. Some versions of the diet attempt to address this by recommending a supplement or multivitamin. However, vitamin pills cannot replace all of the benefits and nutrients of healthy eating (nor do we recommend this.) So, People who like conventional approach more still prefer their best folding elliptical and other home gym equipment for weight loss.

Also Read: What Is The 3-Day Military Diet? What You Need To Know

And although the diet sometimes claims names like the Royal Danish Hospital Diet, there is no true consensus on where this diet comes from or who developed it (it was most certainly not developed by any hospital.) This means that there is no guarantee that it was designed by someone with a real understanding of nutrition, weight-loss and healthy living.

Lastly, overly strict diets like the 13-day diet can be very difficult to follow, and do not set you on the right path towards a sustainable, healthy lifestyle. To err is human, and the best diets are not diets at all; rather, a good diet should be realistic, long-term, and make it easier for you to live healthier day to day.

Should I Try The 13-Day Diet?

The 13-day diet technically works… but only for the 13 days. You will likely gain back all the weight you’ve lost and then some once you are off the diet.

And although the diet claims to boost your metabolism, nutritionists and dieticians agree that it’s far more likely to slow your metabolism (as severe caloric restriction tends to do), which means you’ll be worse off after the diet is over when you begin eating normally.

For these reasons, we absolutely do not recommend the 13-day diet. Why torture yourself for 13 days just to add more weight afterwards? The diet lacks proper nutrition and may wreak havoc on your body, leaving you tried, irritable, moody and nutritionally lacking.

If you still want to try this diet, we STRONGLY recommend that it be overseen by a healthcare professional to ensure safety.

Instead of relying on fad diets like the 13-day metabolism diet, try some of the basic following healthy living tips:

  • Increase your level of activity.
  • Incorporate exercise (both cardio and strength training) into your life, three to six days a week
  • Drink lots of water.
  • Eat plenty of vegetables.
  • Don’t skip meals.
  • Cut down on the amount of processed food you eat.
  • Get enough sleep.
  • Learn to cope with stress.
  • Avoid eating out of boredom.
  • Watch your portion sizes.
  • Indulge every now and again.
  • Keep upright exercise bike in your routine

Simple enough, right?