Understanding weight loss in a Scientific way

When we talk about weight loss, first we need to 

understand what weight is. It

 could be subcutaneous fat or visceral fat...fat that's in the abdomen around the organs now what is this fat?

Well, the fat is the way the body stores energy. It stores it in adipose tissue. A fat, fat tissue, adipose tissue is made up of adipocytes a small amount of connective tissue and out of the sites or adipose tissue and in general is made up of 87% lipids and lipids when we talk about lipids in the body we're generally talking about triglycerides. Triglycerides are called triglycerides, because they have three glycerol groups and these glycerol groups are connected to these long chains of carbon and hydrogen so basically you can see here this is a large complex molecule and there are many many high energy bonds which hold the molecule together in the body. So, the body's basically strong energy in these chemical bonds. Okay, so when the body needs the energy it breaks down these chemical bonds and and removes the energy so basically we had this complex molecule that looks like this so there's you know 55 carbons 104 hydrogen's and six oxygens when this breaks down we end up with a formula a chemical formula that looks like this. So we need to add 78 oxygens and then this makes 55 carbon dioxide's plus 52 molecules of h2o and then plus energy. So the energy again is the energy, that is stored in the high energy bonds of this large and complex molecule when it gets broken down, it is released.

That's how the body stores the energy and so I know this would review for most of you but it's really important to think about when we're talking about weight loss we are talking about a negative energy balance right so in order to lose weight we have to have a negative energy balance. So what does that mean well let's talk a little bit about energy so in order to understand the way that energy works in the body we really have to sort of understand the basic physical print physics principles of energy so we need to talk about the first law of thermodynamics and basically the first law of thermodynamics states that energy is conserved. It can't be created or destroyed. So basically what that means is the energy that we take in to our body over our lifetimes, has to equal the energy that comes out okay so but this is over our entire lifetimes as an organism because the in between the time that energy is going in and energy is coming out lots and lots of energy is being stored. So, energy is being stored in in muscles and in our brains and in any organ that has complex molecules proteins and carbohydrates as well as fat. So, our body is an energy store of chemically stored energy that is stored in these complex molecules. So, when we have excess energy in if energy in is greater than energy out then we end up storing it. Our body ends up storing it in adipose tissue by making extra triglycerides and we get fat okay so let's talk about a very simple formula here so in our bodies energy in has to equal energy out plus energy stored okay now we are concerned about weight loss and remember weight loss means that we need to have a negative energy balance so we're really interested in what's being stored in the adipose tissue. So, I'm going to manipulate this formula we're gonna end up with energy stored equals energy in minus energy out okay simple formula but it's really important to understand the sort of underlying process the underlying concept of where the stored energy is coming from so basically what this is saying is the amount of fat that we have in our body is a consequence of the difference between energy that we take in and energy that we remove and we remove it in various ways and we're going to talk about that in a few minute. Now a lot of people make the assumption that that we have conscious control over all aspects of the energy we take in in the energy that we use so we make a common fallacy which basically states that the amount of fat that we have is a function solely of eating and exercising right so if you want to lose fat or lose weight you need to eat less and exercise more to reduce this distance okay but this is a fallacy because it assumes that we have conscious control over energy in and energy out when in fact we actually have limited control over over different aspects of this of this equation because our body is constantly modulating the amount of energy we take in through our appetite and is we have very little conscious control over most of the energy that we use in our body from a day-to-day basis so this is a fallacy the amount of fat that we have is related to the amount that we eat in the amount that we exercise but there are other factors to consider and that's what we're going to talk about okay one of the major of impacts on the amount of food that we take in or the amount of energy that we take in is our appetite and we're gonna talk in in the next video about exactly what controls that appetite but essentially it's controlled primarily by hormones in our body and what's fascinating about appetite is our body wants to keep our weight the same and in  fact it has a bias against losing weight.

It actually has is less resistant to gaining weight than it is to losing weight so it has a strong bias against losing weight so the more weight that we lose the stronger our appetite becomes okay now another factor is our conscious choices right or willpower if you're working on dieting so what happens is if you are trying to lose weight there is a battle between your willpower and your appetite and the more weight that you lose the stronger your appetite becomes so we know from research that the majority of people fail at dieting and if they're able to diet at all they have a hard time losing more than 10 percent of our body weight because as we get down to less than as we get down to weight loss of more than 10 percent of our body weight or appetite increases so it becomes very very difficult so again you know we talked about a fallacy and the fallacy is that you know this is not just simply a just choice of how much we eat this is not just about willpower well how come people just can't eat less that's because our body is actively fighting against us by increasing the drive to eat okay so let's talk about energy out this gets even more interesting because you know again we think of it just about eating less and exercising more well the fact is that exercise actually only accounts for about 10% of the energy we use from a day-to-day basis what makes up the 90% well basal metabolic rate makes up about 70% of our energy use from day to day in our day to day life basal metabolic rate essentially accounts for sort of ion movements that are that's happening in cells muscle movements of unconscious movement like died you know peristalsis in the gut breathing the heart beating etc so basal metabolic rate and you know what's interesting is the body is really does not like a negative energy balance it wants to maintain this storage of energy so what does it do when we lose weight when this energy store is going down the body actually fights against us and decreases the basal metabolic rate so even if we try to increase this exercise to twenty or thirty percent the body is actin actively fight against us by reducing the amount of energy we're using from our basal metabolic rate okay so 70 plus 10% that's we're only up to 80% so what else is there well there's something called the thermic energy of food and this is basically the amount of energy that we use to digest absorb and metabolize the foods that we eat.

So again it's not something that we have conscious control over in fact the more food that we eat the more thermic energy of food we have now there are some foods that have higher thermic energy values but this is not really an effective way to lose weight because it's not going to increase the percentage all that much if you eat higher fiber foods it tends to have a higher thermic energy so that helps a little bit and eating protein versus fats proteins have a higher thermic energy so they use more energy to digest absorb or metabolize now and then there's also non exercise activities so actually you know it's interesting here is is fidgeting is included here and there's some people that fidget much more than others and they end up burning me up to like 800 calories more per day just because they fidget can be a very annoying habit but it can help you lose weight so what if you increase your exercise well if you started running five miles per day you could increase your exercise up to thirty percent of your energy use okay so if you ran a marathon every day you could increase it even more and that would be significant impact on the amount of energy that you expend but if you increase if you're running five miles per day you can increase your exercise the energy that is expended from exercise to about thirty percent of your total energy expenditure.

But still you can see the major contributors for for the energy expenditures is still not going to be exercised in the body again is actively fighting against weight loss by decrease it will fight against it by decreasing basal metabolic rate and increasing appetite so again I just want to say that the major takeaway here is weight loss you know if it were easy if it was as simple as eating less and exercising more then we would all be walking around thin the reason why it's so difficult to lose weight is because our body is actively working against us because it has a bias against losing stored energy and there's evolutionary reasons for this of course but it fights against losing weight by increasing our appetite and decreasing our basal metabolic rate.