While calories associated with fat are generally considered “bad,” we still need calories (i.e. energy) to survive. Calories are what fuel every organic human process and, naturally, they are obtained from food. Knowing the number of calories per gram of fat is useful for a variety of purposes, from determining how many calories come from fat from the products we eat to establishing a more efficient workout regime. Below you will find both a scientific and more practical approach to understanding calories per gram of fat. But like I said, not all calories are bad. Learn how to start living a healthier lifestyle with this top-rated Think and Eat Rich course.
Let’s begin by getting some numbers into our discussion. It will be illuminating to compare the calories in fat to the calories in some of the other most popular organic compounds:
- Calories in one gram of protein: 4
- Calories in one gram of carbohydrates: 4
- Calories in one gram of alcohol: 7
- Calories in one gram of fat: 9
While these numbers look perfect, they are probably off by a small fraction. I say “probably” because if you try to find how many calories are in fat by looking through health journals, you will see the exact number at quoted anywhere between 8.5 and 9.5 calories. However, 9 calories is generally accepted as the standard and it’s certainly the easiest to plug into equations.
You might also be interested in this great post on how many calories you should burn every day if you want to lose weight.
The Scientific Approach
The scientific approach is actually incredibly interesting. First of all, let’s establish the fact that a calorie was originally defined as a unit of heat and that when we say “calorie” when we are talking about nutritional calories, we are actually referring to kilocalories. This is somewhat confusing as the scientific community clearly separates the two terms.
What 1 Calorie Can Do: I will avoid getting too scientific, because there are several variations of calories, all of them quite small, that slightly change the capabilities of a calorie. But the common way of looking at a calorie is that one scientific calorie provides enough energy (heat) to raise the temperature of one gram water by one degree Celsius. Keep in mind that a food calorie, i.e. a kilocalorie, contains 1000 of these scientific calories. In terms of what one calorie can do, that probably doesn’t sound like a lot. But think about it this way: if you eat 2000 food calories (2,000,000 scientific calories), that’s enough energy to warm more than 4,400 pounds of water (over two tons!) by one degree Celsius.
But it’s easy to et burnt out on science and calorie counting. If you want to move beyond diets and just stating eating healthier, invest in this top-rated course on healthy eating: beyond the diet hype.
The Practical Approach
Now let’s be practical. Take the label on a jar of peanut butter. One serving size is 32 grams and 210 calories. That means the average gram is producing 6.56 calories, which is higher than carbohydrates and proteins but lower than pure fat. If we look at the rest of the label, we find that there are 16g of fat, 6g of carbohydrates, 7g of protein, 2g of fiber and 1g of sugar.
Sorting Your Calories: Now that we know how many calories are in most of these compounds, we can figure out how many calories are coming from each one. This is a great way to figure out whether you’re consuming fat calories or protein calories (or carb, or sugar, etc.):
- 144 calories from fat
- 24 calories from carbs
- 28 calories from protein
- 4 calories from fiber (approximately 2 calories per gram)
- 4 calories from sugar (approximately 4 calories per gram)
That leaves us with a total of 204 calories, which is just under the labels claim of 210. It’s also interesting to note that the label does provide a number for “Calories From Fat”: 140. That’s just four less than what we calculated, but that’s a pretty large discrepancy for people who are anal about counting calories. So what gives? Why the different numbers?
Why The Numbers Are Wrong
So why are the numbers wrong? There are two possible explanations. In our case, the answer is not revelatory. If we add up the grams listed on the label, we get 32, which is what the peanut butter company claims. In this case, they may be using slightly different numbers for calories per gram of fat, protein, carbs, etc. It’s as simple as that.
Missing Grams: You’d be surprised how many foods have “missing grams.” In other words, if you add up all grams, you have a deficit. This is because most manufacturers do not include “insoluble fiber.” This is different from regular fiber in that your body never digests it: it passes through intact. There are 4 calories per gram of insoluble fiber and the manufacturer will naturally want to subtract these calories from the total, since they are never digested. In this case, you will often calculate a higher number of calories than those listed. Fortunately, they are calories you don’t have to worry about.
If you want to learn how to cook healthy food that doesn’t require calorie counting, check out this awesome course by New York chef Cathy Erway on Healthy Cooking Fundamentals.