Let’s start with the basics. What is a calorie?
Simply put, a calorie is a unit of energy, more specifically of heat.
There are actually two classes of calories:
- The first is known as a small calorie or a gram calorie and is the amount of energy needed to raise 1 gram (0.035 oz) 1⁰C (1.8 ⁰F). This is essentially 4.2 joules (3.1 foot pounds) of energy.
- The second, which is the calorie we are all used to, is called a large calorie, dietary calorie, food calorie, or kilogram calorie. There are actually 1000 small calories in one food calorie. This is the amount of energy to increase the temperature of 1 kilogram (2.20 pounds) of water 1⁰C (1.8 ⁰F) and equates to 4.2 kilojoules (4200 joules or 3098 foot pounds of force).
For our purposes, we are only going to worry about the food calorie, or the Cal (notice the capital letter C). For simplicity, I will not capitalize the word “calorie” but just try and remember we are taking about large, food calories not small calories.
Taubes argues in his article that our conception that “a calorie is a calorie” may be very wrong.
For a quick recap, remember that proteins are long strings of amino acids that are abundantly found in muscle tissue (meat) and in beans. However, proteins are found in all cells and are integral to cellular function.
Fats are formed by lipids and are also integral to cellular processes, but are abundantly found in red meat and in some fruits, like the avocado.
Carbohydrates are basically complex sugars found in bread, grains, and sweets.
For a better explanation of fats, carbs, and protein check out this .
This leads to the “calorie counting” dietary regime. The school of thought has been, if you ingest less calories than you burn in a given day, then you are in what is called a “negative energy balance.” Think of this as a negative net calorie count for the day.
The negative energy gap is compensated by your body burning stored calories (fat).
Sustaining a negative energy balance over a longer course of time will then result in weight loss.
The opposite, as most of us already know, is also true.
If you intake more calories than you expend you are in a positive energy balance and will store the rest of the energy as fat - gaining weight.
The issue with this is there are a lot of people that still have a very hard time losing weight, even if they have been counting their calories.
The culprit may be what we have long feared – carbohydrates.
Carbohydrates are complex sugars, usually starch, found in foods like cereals, bread, and pasta. Simple carbohydrates, such as sugar, are found in candy and desserts.
Carbohydrates also stimulate secretion of insulin, which is a hormone responsible, among other things, for storing fat in fat cells, according to the article.
This led to a shift in understanding, according to Taubes.
Since carbs are low in fat, many believed that ingesting high amounts of carbohydrates will keep us thin as well as heart healthy.
- First, obese volunteers were semi-starved until they lost between 10 -15% of their body weight. People who have lost this much weight are susceptible to gaining it back because their energy drops to much lower levels than people of the same weight naturally. Here lies the issue - these people now have to fight their hunger craves just to maintain their weight.
- The subject’s calorie expenditures were monitored and were only fed the same amount of calories that they expended throughout the day.
- Even though each subject received the same caloric amount, they were rotated into three very different diets for one month at a time. One diet was low in fat and high in carbohydrates which included fruits, whole grains, vegetables, and lean protein. Another diet had a low glycemic index which includes fewer carbohydrates in total but which are harder to digest – beans and non-starchy vegetables. The third diet was the good-old Atkins diet: high fat and protein and almost no carbs.
Results of the study:
- The fewer the carbs ingested, the more energy the subjects expended.
- Most of the subjects on the Atkin’s diet expended only 100 calories less per day than they did at their former weights and 21 of them expended more energy than they did when they were heavier.
- The Atkin’s diet groups experienced 300 calories burned per day more than the high carb subjects and 150 more per day than the low-glycemic index subjects. The high carb/low fat subjects had to exercise for an hour a day just to keep up with the Atkin’s subjects.
- It seems that weight loss may cause “metabolic adaptations” which make it harder to maintain body weight after weight loss has occurred.
- We have to start looking at both the quality and quantity of the carbohydrates we ingest because they can keep us from being lean.
- Many people may be genetically predisposed to weight gain from carbohydrates.
As you can already see, this is a very controversial conclusion.
It would seem , in one light, that the American Heart Association is wrong in that low-fat, high-carb diets will make us lean. It may actually put us at risk for disease.
Yet in another vein, it would seem that eating a diet high in fats and low in carbs will keep us leaner but perhaps put us at risk for heart disease.
More research has to be done but I think that the implications of the research are very intriguing and definitely worth further study – something that Dr. Ludwig and his team are already looking into.
Think about it!