What does it mean if I burn more calories than I intake?

Question

I'm really unhealthy. I have virtually no physical activity.

Well I'm trying to change this. So to start out, I'm doing couch to 5k. If you don't know what it is, it's just a beginner running routine with a mix of jogging and walking.

I started today. I did my first run. But now I'm trying to also focus on my caloric intake so I don't just eat what I've burned off. But I'm confused.

I have an app called my fitness pal
I don't know how accurate it is, But according to this app, my 30 minutes of exercise burned about 330 calories.

It also has a Calorie log. According to this log, I ingested 1300 calories but my maximum allowed is 1500. And then it says I burned off 330 calories which means there's 1000 left. So in theory I could eat 500 more calories and still be fine, right? That just doesn't make sense to me. Because even though I ate less calories than it says to eat, I ate junk food. I ate pizza rolls, chips and a bacon cheese burger throughout the day. I know that's unhealthy food. Next time I go grocery shopping I'm buying healthier stuff. But today that's what I had. And what I don't get is that I thought it was grams of fat that caused me to be fat, not calories. Those foods have about 50 grams of fat in total. Shouldn't I be worried about that and not calories?

I don't understand. Why monitor calories but not how much fat I take in? Which one do I worry about to not cancel out the running I do?

I also have a friend who told me that without supplements, running isn't going to help me lose very much weight and I should just go to the gym instead. Is this true? Am I wasting my time trying to lose weight If all I do is jog, without taking any weight loss supplements?

Answer 1

Explaining all of this in detail will require whole books and not just a few paragraphs, so I'll try to be as brief and concise as possible.

Think of your body as a machine that requires energy -which we count in calories- to function. Give it exactly the energy it needs, and you will neither gain or lose weight. Give it more, and you will gain; less, and you will lose.

BMR, or Basal Metabolic Rate, is the calories your body requires to survive in a comatose state (that is, doing absolutely nothing but basic vital functions). It depends on things such as your age, gender, height, weight and body fat percentage.

Since most of us are not in a coma, we tend to care more about TDEE (Total Daily Energy Expenditure), which as it name indicates takes into account physical activity.

Take a look at this simple example: John works in an office as a programmer 8 hours a day, drives to work and back and spends the evenings at his couch watching TV. One day John gets fired for spending way too much time on StackExchange. He has to sell his car -so from now on he will walk everywhere- and finds a new job in construction, working 12 hours a day.

John is the same person that he was a couple of weeks before, and his BMR remains unchanged. However, his much increased daily physical activity means that his body will require much more energy, and thus his TDEE will be considerably higher than before. So if his diet remains the same, he will more than likely lose weight.

Eating less calories than your TDEE is called caloric deficit, and it will make you lose weight. Eating exactly the same calories as your TDEE is called being at maintenance, and you will neither gain or lose weight. Eating more calories than your TDEE is called caloric surplus, and it will make you gain weight.

Regarding fats, the are not bad for you. In fact, they're necessary for your body to function properties. As seen above, eating fats will not make you fat, being at a surplus will. The reason why most people identify fats with getting fat is because they're very caloric (1g of fat equals about 9 calories, compared to 4 for protein and carbs). Extreme example: if your TDEE was 2000 cal and all you ate everyday was 1800 cal of pure fat, you would lose weight.

PS: Weight supplements are irrelevant. Go to the gym.

Answer 2

TL;DR Change your lifestyle by making reduced portions at meals and some amount of daily exercise a habit and you will lose weight.

Long Answer:

It also has a Calorie log. According to this log, I ingested 1300 calories but my maximum allowed is 1500. And then it says I burned off 330 calories which means there's 1000 left. So in theory I could eat 500 more calories and still be fine, right?

Wrong. If you want to lose weight then calories burned needs to exceed calories taken in. Burn of calories includes BMR as described by Eric Trigo, so you don't necessarily have to exercise to the tune of 1500 calories per day. You can estimate your BMR online using any number of tools, for example this one.

That just doesn't make sense to me. Because even though I ate less calories than it says to eat, I ate junk food. I ate pizza rolls, chips and a bacon cheese burger throughout the day. I know that's unhealthy food. Next time I go grocery shopping I'm buying healthier stuff. But today that's what I had. And what I don't get is that I thought it was grams of fat that caused me to be fat, not calories. Those foods have about 50 grams of fat in total. Shouldn't I be worried about that and not calories?

Eating simple sugars like those found in junk foods, or excess fat, or excess salt, can lead to other health complications like diabetes and hypertension. There are also issues with junk food not really satisfying hunger pangs in the same way that healthier foods do, which is the real challenge from a weight loss perspective.

Why monitor calories but not how much fat I take in? Which one do I worry about to not cancel out the running I do?

Monitoring fat intake rather than calories is more important if you have for example issues with high cholesterol. From a weight loss perspective you are interested in reducing calories. A lot of people don't understand that you can minimize my fat intake but still take in a grotesque amount of calories. For example if I drink soda pop I'll probably take in more calories than if I drink the same amount of whole milk, but drinking soda gives me zero fat while whole milk is something like 3% fat.

I also have a friend who told me that without supplements, running isn't going to help me lose very much weight and I should just go to the gym instead. Is this true? Am I wasting my time trying to lose weight If all I do is jog, without taking any weight loss supplements?

Any kind of physical activity will increase calorie burn and thus help you lose weight. You don't need supplements, just eat less (target half as much... but realistically you will probably only be able to sustain portions reduced by 25% from what you eat today) and exercise. Several years ago I dropped 30 pounds (a bit less than 15% of my body weight) in six months by cutting portion sizes and walking 4 miles a day. That is anecdotal, your experience will likely be different, but serves to illustrate the point that you can get results without buying into the fitness industry.