Knowledge is Healing

So you want to lose weight and want to know how many calories you should eat in order to achieve that…

First of all let’s remind us the number of calories contained in fats, proteins and carbohydrates:

1 gram of fat = 9 kilocalories ~ 37 kilojoules

1 gram of protein = 4 kilocalories ~ 16 kilojoules

1 gram of carbohydrates = 4 kilocalories ~ 16 kilojoules

And some more calorie values:

1 gram of alcohol = 7 kilocalories

1 gram of dietary fiber = 3 kilocalories

Having all these values in mind you can easily calculate the number of calories in food you eat every day. And how much calories you need a day is another question:

How to estimate your daily caloric needs

You can estimate your daily caloric intake with the Harris-Benedict formula. It helps you calculate your basal metabolic rate (BMR), i.e. the optimum amount of energy your body needs to function.

Let’s calculate your BMR

To do that you need to use your current weight, height and age in step ONE. It’s easy:

Harris-Benedict formula for Women:

655 + (4.3 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)

Harris-Benedict formula for Men:

66 + (6.3 x weight in pounds) + (12.9 x height in inches) - (6.8 x age in years)

Take your daily activities into account in step TWO:

• Add 20% of your BMR to your current BMR if you are sedentary: (0.2*BMR) + BMR

Means you spend all day sitting in a chair: for example working with a computer in a bank, home, office, etc.

• Add 30% of your BMR to your current BMR if you are lightly active: (0.3*BMR) + BMR

For example if you exercise 2-3 times a week.

• Add 40% of your BMR to your current BMR if you are moderately active: (0.4*BMR) + BMR

For example if you exercise 4-5 times a week.

• Add 50% of your BMR to your current BMR if you are very active: (0.5*BMR) + BMR

If you exercise every day of the week or for prolonged periods of time. For example if you are a fitness trainer.

• Add 60% of your BMR to your current BMR if you are extra active: (0.6*BMR) + BMR

If you are a professional athlete or if you work hard labor job.

How knowing your BMR will help you lose weight?

Knowing your BMR means you are aware of how much calories you need a day to keep your current weight. However, if you want to lose weight you need to cut your daily caloric intake (eat fewer calories) or burn the extra calories (through some activities). As a result you should keep your daily calorie intake lower than your BMR. How much lower? That’s the question… But before that you need to know:

Some more nutrition facts from Wikipedia:

Because human adipose (fat) tissue contains about 87% lipids, one kilogram of it stores the caloric energy of roughly 870 grams of pure fat, or 7800 kcal. In principle one has to create a 7800 kcal deficit or surplus between energy intake and use to lose or gain 1 kg of body fat, respectively, or 3500 kcal per pound. However, if one eats 7800 kcal more than the body needs, one won’t necessarily gain 1 kg of fat, since muscle and other tissues may be built. In the same way, if one eats 7800 kcal less than their maintenance level, they may not lose 1 kg of fat, since muscle and sugars may be metabolized to generate energy.

In short and still roughly speaking – in order to lose 1 pound a week you need to eat 500 calories less a day or burn those calories through exercising or other activities. For optimal results you should combine the two methods – eat 250 calories less and burn the rest 250 exercising.

Gradual weight loss is the healthiest way to achieve your desired weight

More than 2 pounds a week is not very healthy and the lost weight is not permanent. 1 to 2 pounds a week is natural weight loss – good for you and your body. You will be loosing weight with a smile on your face and won’t even notice you are dieting, because you will be dieting naturally.

Calorie is the non-SI unit of measurement for energy. The SI unit of measurement for energy is joule. There are two types of calories:

Small calorie (aka gram calorie) is the energy needed to increase the temperature of 1 g (gram) of water by 1 degree Celsius (1.8 Fahrenheit).
1 cal equals to 4.184 joules (cal is the symbol for gram calorie)

Large calorie (aka kilogram calorie) is the energy needed to raise the temperature of 1 kg (kilogram) of water with 1 degree Celsius (1.8 Fahrenheit).
1 kcal equals to 4.184 kilojoules = 4184 joules = 1000 cals (kcal is the symbol for kilogram calorie)

Although not a SI unit kilocalories are still the most common measurements for food energy. Hence the most common misconception that occurs when we talk about calories in food – despite we read calories or cals on food packages, the labeling actually refers to kilocalories when we talk about food.

For example: If a pack of crackers has 400 calories (or cals), it turns out that the calories (or cals) marked on the crackers package are actually kilocalories (or kcals), so it would be correct if written 400 kilocalories (or 400 kcals), but usually it’s not.

Often the word “calorie” (referring to kilocalorie) is capitalized (Calorie) in order to be distinguished from the small (gram) calorie, but this is not effective outside the specific context, so it’s practically useless.

The name “calorie” (referring to kilocalorie) is often used in medical sciences and non-scientific contexts. Whereas, the name “calorie” (referring strictly to the gram calorie) is used in scientific contexts such as chemistry and physics. Here’s why it is needed to be inferred from the context whether the gram calorie or the kilogram calorie is intended.

When we talk about exercises the same rule as in non-scientific context applies.

For example: If you normally burn 100 Calories (or cals) on the treadmill technically that refers to 100 kilocalories (or kcals).

Do you know that a recent research showed that using artificial sweeteners might be related to weight gain? Amazing isn’t it?

The research was conducted by a team of scientists from Purdue University in USA and was published in the journal Behavioral Neuroscience.

In the experiment were used two groups of rats - each fed with yoghurt. The first group was fed with artificial sweetened yoghurt and the second one with crystal sugar sweetened yoghurt. After that each group was given food – plenty of it. The results were amazing:

The group of rats fed with yoghurt sweetened with artificial sweetener gained more weight and put on more fat compared to the other group.

Imagine if you drink your favorite morning coffee sweetened with saccharin and then eat up a lot of the chocolates and sweets from the local vending machine. Eventually you gain weight, whereas your closest coworker drinks her coffee with sugar and stays the same weight. Sound terrible, but it could be true…

It is all explained by the theory for sweet expectations:

Normally the sweet taste in the mouth primes the metabolism for the arrival of more high caloric or sweet meal. When that meal does not arrive, according to the theory, the body might get confused and have problems to regulate its appetite when other food is present around.

If this theory is true the low-calorie artificial sweeteners could have a similar effect.

My opinion

Do not forget that artificial sweeteners have helped so many people to lose weight when eating foods sweetened with them. This is still a very solid fact and one single (although very interesting) study conducted using rats does not prove for sure anything and cannot overrule the many health benefits of using artificial sweeteners all at once.

I will try this theory myself and see if I feel the same way. Currently I am a sugar lover and I will be happy if all this turns out to be true, so I wouldn’t need to switch to sweeteners in order to lose weight.

Source: BBC News (February 2008)