Why is it so hard to lose weight?

Before I start talking, let me tell you what medical courses I have taken related to this topic.
I have taken my MNE block, Metabolism, Nutrition, and Endocrinology.
Here we learn all about how the human body takes in food and makes it into energy, store energy, how hormones play a role in that, and the importance of nutrition in promoting positive development and growth as well as maintaining the body.

Certain classes from this block include: Diabetes, Obesity, and Bariatric Surgery.
(While I am not specifically talking about diabetes and bariatric surgery today, there are a lot of things related to the human body, especially hormones and other things my professors talked about in those classes that are important for understanding about weight.

Another important thing is that. There is a lot data, charts, graphs, research papers in my courses that I can't put onto this post because it would make it way too long and crazy. I just ask that you believe what I write here because all I'm telling you is what I learned and I am looking at all of my lecture sides, notes, and data as I write this post, so I won't make any mistakes (even though I have this all memorized)

Okay, so let's get down to it. This will be long. Feel free to take breaks in between or read more at a later time. I'm sorry if this is dry or boring. =P

So, when I was younger. I thought that it was mainly the person's fault that they could not lose weight. As in, they were lazy, not motivated enough, The reason being, I happen to have many friends who were on the heavier side and they changed and lost weight over the years and I saw their progress and attributed it all to hard work and determination. Of course, that is a very important factor in the goal of weight loss, but I was ignorant. Because, it's actually very hard to lose weight.

So, why is it so hard to lose weight? Why is it so easy to gain weight? The core of the matter is that we really don't know. There are factors that can contribute to weight loss and weight gain, but no one has found the ultimate answer for why it is easy or difficult for some people to lose or gain weight.

Here are some things to think about:
There's that homeostasis theory right? The set-point theory, that your body will maintain a certain weight and try to keep it that way, try to keep it in a stable range. Why? Because to drastically gain or lose weight would put so much pressure on your body's system, it won't be able to adjust in time and you would probably die.
But if we have set-point, why are people, on average, getting larger/heavier, every year? Shouldn't our bodies maintain that set-point and keep you in a decent range? But, apparently not, people are getting bigger and seem to not have a set-point. (However, in recent literature, it says we are gradually tapering off at a set-point that is much higher than it was a generation ago)
Another thing to ponder is, okay, fine. I want to lose weight. Should be like physics right? The more I eat, the more energy I consume and store, so what I should do, is just eat less. A decreased/lower input than normal will decrease my weight. Not that easy actually. For some people it works, but research shows that you end up not losing as much as you wanted and also, if you don't maintain that decreased input of food/calories, and go back to what you were eating normally, you'll gain all that weight back again. So, in reality, it's not as simple as eating less.

To the facts:
So for the most part, people do have a set-point for their weight (why that set-point is changing and increasing so easily is the current mystery) and it is really difficult to get out of that set-point to make a permanent change in weight (hence, it's not as simple as eating less).

A lot of what controls weight is unfortunately out of your control.
Energy Expenditure is what our body does with the food we eat and it consists of:
1) Resting metabolic rate/RMR (normal body maintenance to survive) = 60-70%
2) Thermogenic proccesses (energy used to digest food and is used as heat) = ~10%
3) Growth (further development of the body, especially for children and adolescents) = ~2%
4) Physical activity = 20-30%

So, this list means, that the majority of your body's control of what you eat is in RMR and how you get your RMR is from your genes, your genetics. And so you can't change your genetics (at least for now you can't), and so if your metabolism tends to be very efficient and break down food really well, it's going to produce more energy than a person who has a poorer metabolism (who can't digest and absorb nutrients very well) and have more energy to store. OR, if your metabolism tends to use up energy very quickly, it is easier to take energy out of storage/fat and use it, than if your metabolism is slower and takes more time to burn calories.

There are also many people with genetic predispositions as well as genetic mutations that may make it easier to gain weight or keep the weight (such as Leptin hormone or Leptin receptor mutations) However, for the mutation part, that is relatively very rare.

There are some people with hormone problems or "glandular problems" and over-produce or under-produce hormones that cause them to gain weight or keep weight easily (such as hypothyroidism and cushing's disease or syndrome). However, that too is relatively very rare.

And so, the problem that most people seem to have is that they tend to over-eat on high-calorie processed food in larger portions, somehow break their set-point, and with all that extra energy, store it in fat.

We also have the "starving/conserving hypothesis" (that's not the official name, I forgot it) that the human body was made to store food because a super long time ago, ancient humans didn't have much to eat, so it was best to be able to store as much food as possible to survive. And I believe that, that hypothesis still stands strong today and is probably a strong contribution to why people tend to keep the weight they gained.

Big Picture
So overall, a lot of things are pre-determined in a way from genetics. Your resting metabolic weight really determines how well and how much process, absorb, and store energy. We all have a set-point that is very hard to change, and our bodies naturally want to store energy. And since about 20-30% of physical exercise influences Energy Expenditure, that means you really have to work hard in your physical exercise, to overcome that 60-70%. It's not impossible okay, if you want to change, you can do it. It's going to take a lot of patience, will-power, hard-work and time, but if you are willing to put in the effort, you can make changes in your life.

Other advice
Exercising is good for your but of course, it's not the only way to lose weight. Usually the best way to lose weight in a healthy manner (and also to lose weight to be healthier) is a combination of exercise and appropriate nutrition and (depending on your age and circumstances) eating less.
The best way is to work with your doctor and/or nutritionist and/or dietitian to make a plan that works best for you and stick to that plan! This is not some temporary diet for a bikini body okay, this is a life style change for your health and well-being.

I hope that this post was informative and helpful to you! Feel free to write any comments and questions in the comment box below! Thank you for reading and I will see you later! =)