is a measurement of energy, it is exactly how much energy you would need to heat one gram of water by one degree celcius. In a nutritional context we typically work with Kcals, or 1000 calories (which would heat one kilogram of water by one degree C.) For the purpose of simplicity I'll simply refer to Kcals as calories. Since a calorie is a unit of energy, we can express it in other ways. For example, 1 calorie = 4184
. It also equals
This enables us do fun things such as figuring out the approximate caloric energy of the
that wiped out the dinosaurs (it's about 15 quadrillion calories- or 355 trillion strips of bacon).
require energy to live
. We use this energy for everything the body physically does. Everything from riding a bike, talking to a friend, beating your heart, to even just thinking about stuff- it can all happen because we supply ourselves with energy. Without that intake, the system will falter and in no uncertain terms
We get our energy from the food we eat. During
the body absorbs
. These are the
. It also absorbs what we call
, which are
. We don't derive energy from micro nutrients so we can skip them for the purpose of this article- but we do derive energy from the macro nutrients. And we measure that energy in... calories.
1 gram of carbohydrate = 4 calories
1 gram of protein = 4 calories
1 gram of fat = 9 calories
So we know we require calories to live. And we know calories come from food. How do we figure out how
calories we should consume? The number will be different for each individual. The factors include (but may not be limited to) your gender, age, weight, height, and activity level. They all come together to give us your
, or the number of calories you should consume each day to match the number of calories you use each day, and thus maintain your current body composition. (You can get a
idea of your caloric needs by using an online estimation calculator
These are the basics. What comes next is pretty cool, because your body is actually
where your survival is concerned (thanks to tens of thousands of years of
). And as you'll see, this makes it pretty straight forward for us to make changes.
Scenario 1: A regular, day to day
consumption of food
What does the body do when it is presented with too many calories / too much energy? It doesn't just discard what it doesn't need. It holds on to it for use later. That means it is stored as fat and/or muscle tissue (the individual gains weight).
Scenario 2: A regular, day to day
consumption of food
What does the body do when it is NOT presented with the calories / energy that it needs to function? The body doesn't just die, it looks instead for all available resources so it can continue living. That means it will burn fat and/or muscle tissue to feed itself (the individual loses weight).
And, drum roll please... that is how ALL weight gain or weight loss works, period.
(weight loss over time)
The proof isn't in the pudding, it's in the scientific literature
The above information has been proven again and again scientifically, and is used worldwide by governments and serious organizations. Objecting to the notion of calories in, calories out is akin to objecting to the law of thermodynamics itself. The law applies to humans just like any other closed system (
and you are no exception
). It's not the types of calories you consume, but
how many of them you consume
. This means that yes,
you can lose weight eating only junk foods
, and you can
gain weight eating only unprocessed / natural foods
. You may have to work hard to do either of these things, and it may not be the best idea for your health overall (with the junk food example), but that doesn't change the basic fundamental truth of energy intake which is what I want to emphasize here.
Despite all of this, it hasn't stopped fitness gurus and book authors from declaring the reverse. These people will typically prioritize the
of calories one consumes, rather than the
one consumes, in one way or another. Carbs are bad for you... right?
But wait, I went on the (insert a popular fad diet) plan and lost 15 lbs, and never felt better in my life! This means that there is obviously something to (the particulars of that fad diet), and that people shouldn't just focus on calories in / calories out."
Not so fast. Here's the thing- fad diets can and sometimes do work, no doubt about it. But it isn't because you stopping eating certain foods, started eating at only certain times, started eating only organic foods, or etc. It's because the diet you went on- in one way or another- caused you to consume fewer calories than your body required to maintain your weight, and thus thanks to the laws of physics, you lost weight. This is the reason, even
For example, lots of people have reported losing weight with
low carb diets
. Because, drastically restricting (or eliminating) an entire macro nutrient group also means you are restricting (or eliminating) a large number of
from your diet. And, no surprise, this is also true of
low fat diets
(remember the 80's?) It's a subtle but very important point to recognize the actual mechanism at play, because it changes the dialog pretty significantly.
(...evil? or perhaps not?)
Do you enjoy the diet you are on, even if it happens to be a
Is it helping you meet your goals? And is it sustainable over the long term? As long as you aren't
missing crucial nutrients
and are maintaining a
healthy relationship to food psychologically
, then keep it up!
If not- consider what I believe to be the "end all, be all" of dietary approaches:
. The concept in a nutshell is very simple: Figure out what your caloric (or macro nutrient) needs are for your goals, then make eating that number of calories (or macros) your goal day to day. Notice that there are no restrictions on
you can or can't eat, or when. That's entirely up to you. In fact it's entirely possible to enjoy foods that most people wouldn't expect you could while dieting on a regular basis, as long as it fits in with your goals. Enjoy pop-tarts? I do. Can you fit one in to your caloric budget today?
(you can eat these)
Flexible dieting simply means you know how much you need to reach your goals. Being able to continue eating your favorite foods means it will be a hell of a lot easier to adhere to your plan when dieting down, and you also avoid the "yo-yo dieting" scenario. Does this mean you have to
Perhaps in the short run, yes. I would recommend it if you haven't done it before. But in the long run, no, and
here is a great article that talks about that.
Going over how to get started with your own plan would make this article about 6 times longer than it is, and it's already too long, so I'll simply point you to what I feel is the best resources available today:
- This is a massive guide that covers just about every aspect of getting started with dieting / nutrition that exists. And it's also where I got started. I recommend reading it all of course, but the nice thing is that it's broken up in to a table of contents so you can reach out for specific information if desired.
And that's it. How about a quick FAQ?
Frequently Asked Questions (that I imagined you asking)
What about overall health? Shouldn't that be a consideration in how I structure my diet?
Yes. Just because you can eat whatever you want and still maintain or lose weight, doesn't mean you necessarily should. :) I think it's a great idea to eat a well balanced diet that contains all of the macro nutrients, essential micro nutrients, fiber, and that includes several servings of fruits or vegetables each day. This is a huge topic of course that is much larger than the scope of this article, so I'll simply point you to the USDA's site,
where you can learn almost everything you need to know about eating for health. Having said that, I firmly believe there is no harm in occasional junk food- just make sure it doesn't play a large role in your overall eating habits.
What about exercise? You didn't mention that anywhere.
I love exercise. Specifically weight training and running. I'll almost certainly write more about those in the future. But for the purpose of this article, I left it out because I actually think it's one of the worst ways to lose weight with any consistently. There are two reasons why I say this:
1, The amount of work it takes to burn calories, vs. the amount of "work" it takes to resist eating the same number of calories is appallingly large- in my opinion. For example, at my height and weight I would need to run 3.5 miles to burn off a
bagel with cream cheese
. That wouldn't even fill me up for breakfast, and running that far would take me at least 25-30 minutes (on a very good day). On the other hand, simply
the bagel in the first place is akin to doing that 3.5 mile run. And I can easily do that every day.
2, Exercising regularly enough to consistently lose weight without any diet modification is actually pretty difficult. Since you'll want to be in a caloric deficit nearly every day while dieting, you'll need to exercise everyday, which isn't easy for everyone to manage. Also, it's entirely possible that something will come up that prevents you from exercising, such as a change of work hours, an injury, or any number of things. Heck, doing that much exercise might even be the reason you get injured in the first place.
As I mentioned before, I love exercise and am not trying to dissuade anyone from doing it, I just don't think it's a good way to create a caloric deficit. But there are many other good reasons to do it. If anything, I would instead recommend a diet based caloric deficit together with casual exercise. For the win!
I agree or disagree with something you said, have comments I'd like to share, and/or questions about this subject.
Join me in the comment section below! And thanks for reading.
a health professional, just a fitness nerd. You should always consult your doctor before starting any new diet or exercise plan.)