I’m just confused on how losing weight actually works. So if I cut myself down to 1500 calories a day, I would have to burn like 2000 calories to lose weight? That just seems like a lot of exercising to me, especially because I’m juggling a job and highschool still. Could you guys explain it to me in a better sense?
In: Biology
You’ve got the basics. Burn more calories than you consume, you’ll lose weight.
How you do it is where it gets complicated and depends on your body (e.g. cardio vs. lifting weights, different calorie-restricted diets, etc.). Your goals are also important – are you losing weight for health reasons, or to play a certain sport, or for other lifestyle reasons?
You don’t burn all 2000 of those calories just from exercise.
Everyone has a BMR (basal metabolic rate) which is the amount of calories they burn a day just by existing basically. This is calculated based on height, weight, age & gender, – you can calculate it [here](https://www.calculator.net/bmr-calculator.html). This will be a good estimate, but there are other factors: for example, people with higher muscle mass will have a higher BMR, and people who don’t sleep much/don’t get enough deep sleep will burn less.
You lose weight in every activity you do including breathing. Even when you are sitting down your heart is pumping. This takes energy which burns calories is a measurement of. So even if you do nothing all day there is an amount of calories you naturally burn. You can find this amount online by looking for what is called a BMR or Basel metabolic rate calculator. This is a rough estimate of how many calories you burn a day without adding any exercise. The amount of calories you burn from just being alive plus the calories you burn from exercise is your calories burned per day. Then you eat less calories you can lose weight.
[https://www.calculator.net/bmr-calculator.html](https://www.calculator.net/bmr-calculator.html)
[https://www.choosemyplate.gov/node/5799](https://www.choosemyplate.gov/node/5799)
It’s a combination of calorie deficit and insulin control.
Control calories by choosing foods that are more nutritious, less processed and control insulin by not snacking or chronic over eating high sugar foods that would lead to constant elevated insulin levels which will block all body fat burning.
One of the best minds on this subject is Dr. Ben Bikman who studies and teaches fat metabolism.
Every night to keep warm, you need to burn 3 logs of wood in the stove.
Every morning, you go out into the forest and get 4 new logs.
One day, you realize you have 100 extra logs, far more extra than you ever need.
This is how you gain weight.
So you start collecting only 2 logs every day, because even though you have extra, you want to keep the routine (not feel like you’re starving).
Many days later, you’ve used 75 of your 100 extra logs and are down to 25 extra, a healthy backup.
That how you lose weight.
+++
Read the r/fitness wiki article Losing Weight 101 ([https://thefitness.wiki/weight-loss-101/](https://thefitness.wiki/weight-loss-101/)) for more detailed information.
PS: After you read the Wiki you’ll get why I say this: you’re probably already burning 2000 calories a day just by being alive, especially in your teens.
Yes, doing enough exercise to burn 2000 calories IS a lot of work! Thank goodness, your body is willing to help out. Virtually everything you do burns calories. Breathing. Blinking. Sitting. Standing. Sleeping, even!
Once you determine approximately how many calories your body burns per day (even with you “doing” absolutely nothing), you’ll know how many extra calories you’ll need to expend in order to lose weight.
How do you find this out? Glad you asked! It is called your Basal Metabolic Rate (BMR). It is alternately called your Resting Metabolic Rate (RMR). It factors in your age, gender, height and current weight. There are many calculators online where you can plug in that info to get your result.
Let’s say your BMR comes out to around 1600. If you eat less than that, you should eventually lose weight. Activities you do during the day will increase how much weight you lose.
Hope that helps!
Remember, just living burns calories. Your body needs to breathe, pump blood, run your brain, and a million other things that all burn calories. The amount of calories your body uses just staying alive is called your basal metabolic rate, or BMR. Any calories you burn through exercise or movement would be added to that.
So, if you eat 1500 calories, that doesn’t mean you need to do 2000 calories worth of exercise. Let’s take me for example. I can use a calculator like [this](https://www.active.com/fitness/calculators/bmr) to estimate my BMR. For me (a tall guy) it’s 2000 calories. So even if I slept all day, I would lose weight on a 1500 calorie diet. If I use the caloric needs calculator on that site, which adds in the calories you burn from activity, it says I burn 2700 calories even if I’m sedentary, and 3000 calories if I am mildly active, so I could lose weight even on a 2500 calorie diet.
You burn a bunch of calories just being alive (breathing, generating heat, etc).
You can either cut your caloric intake below that number, or exercise to burn extra calories.
Eg, if you burn 1800 calories just being alive, and normally intake 2000, you could cut your intake down to 1500, or exercise to burn off 500.
Exercise is generally the healthier option, of course, since you have less worry about not getting enough nutrition. Plus working out has the added benefit of building muscle mass, which increases the “base” calories you burn by doing nothing. But it has its downsides relative to dieting too.
Your are burning calories simply by breathing, moving, pumping blood, thinking. Just being alive is burning calories. How many depends a bit on your age, size, and day to day lifestyle.
So the basic rule of “calories in calories out” is –
all about burning more than you consume.
A rough estimate of baseline calories for a guy that is 5’10”, 190lbs, 30yrs old, and has a pretty sedentary lifestyle is aprox 2100 calories a day. That means at 2100 calories a day he won’t really lose or gain. His BMR is aprox 1820 calories a day. That’s how much his body is burning just by being alive. So if he eats only 1800 calories a day he’s going to actually lose weight because he’s not just alive, he’s also thinking and getting up and moving around and showering and whatever else he’s doing. That’s why he needs those aprox 300 other calories to stay more of less then same weight.
That’s an over simplified explanation.
As for losing weight, it’s 95% diets 5% exercise. No mater how much you exercise you need to be at a deficit in the “calories in/out” equation. And exercise, for an average human, only burns a few hundred calories at best.
Lots of useful answers, I’ll just add this: don’t focus on your weight, look at your body fat. Muscles weigh more than fat.
Eating more vegetable protein and fats and fewer carbs will help train your body to use fat more efficiently. Remember to drink lots of water.
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