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Thursday, December 10, 2015

Why is weight loss so hard?

Why on earth is losing weight so hard?! Well to be honest, weight loss isn’t all that hard. If you were to simply stop eating you would lose weight. Obviously this is not a viable option so how can we go about weight loss without starving ourselves or spending hours at the gym? The answer: Moderation. And no I’m not talking about eating in moderation because no one likes to do that; although that would help. I'm talking about losing weight in moderation. 

If we look at the concept of weight loss in an extremely over-simplified matter, it really comes down to energy balance and by that I mean the overall net amount of calories in versus calories out. If we burn what we eat then we are in energy balance and we maintain our current weight. If we burn more than we consume then we lose weight... you get the picture. Well then shouldn’t the solution be just to eat a little bit less and exercise a little bit more? Well kind of.  In reality you can't just keep cutting calories little by litter every day to elicit weight loss as eventually you would have to cut down to zero; again not very practical. 

So again I ask, why is long weight and more importantly maintaining weight loss so hard?
Well if we look at what factors influence our daily calorie expenditure it can be broken down in to 4 main categories:


1) Basal Metabolic Rate: Which is our baseline metabolism or our resting energy expenditure, essentially the amount of energy it takes just to keep us alive. If we were to lay on the couch all day (i.e. My Saturdays during football season) this is how many calories we would burn.  This number is heavily dependent upon the amount of lean body mass aka muscle we have. I'll explain why this is important later.

2). Thermic Effect of Food: The amount of energy it takes to digest the food we eat. That's right, we burn calories just by eating. Especially foods that are high in protein, which is why you get the meat sweats trying to win that 72 oz. steak challenge.

3). Activity Level: This number is influenced by how active we are throughout the day. Different occupations will result in different activity levels throughout the day (i.e. a desk jockey versus a mailman) and therefore may influence the amount of calories you burn.

4). Exercise: Last but not least, exercise....The number of painful minutes you spend at the gym getting your sweat on, watching the "calories burned" number go up on the elliptical instantly determining how many mini-snickers that equals.


So which factor carries the most "weight" (pun intended) in terms of how many calories we burn each day? Believe it or not the answer is our basal metabolic rate which makes up roughly 60-70% of our total daily calorie expenditure.  So what does this have to do with losing weight? Again, can't we just spend a few extra minutes on the elliptical to increase the number of calories we burn and tilt the energy balance scale towards a calorie deficit for the day and watch the scale change? In the short, yes this would give you a negative calorie balance for the day and possibly even lead to some weight loss over time. BUT this may end up making it more difficult to continue losing weight and/or keep the weight off in the long run. Why you ask? Well, if we look back at the factors that influence calorie expenditure and observe what changes occur during a weight loss program you'll see why.  First, as people lose WEIGHT a lot of the times this means all weight, fat, muscle and sometimes even bone density all of which are not necessarily ideal, with the exception of body fat. When this happens, you are losing metabolically active tissue aka lean body mass and as a result you experience a decrease in resting energy expenditure.

As a result, you burn less calories each day just because you thought it was a good idea to lose weight. Okay, so your daily energy expenditure is now lower, so you try to overcompensate by eating less and less calories each day? Now remember back to factor 2 on things that influence your daily energy expenditure.  By eating less throughout the day you will be missing out on the thermic effect of food, it sounds odd but eating less food will reduce your overall calorie expenditure throughout the day.  Alright, so losing weight is bad, cutting calories doesn’t work, what about exercising more? Well, if you have already lost weight or are in the process of losing weight, every time you go out and exercise you will be expending less and less calories per workout. Why? Well, you are lighter so it takes less energy (aka calories) do to the work. In addition, you also have less metabolically active tissue which will also reduce your energy expenditure for that workout.  AND, to top it off, research has also found an increase in mitochondrial (our cell’s energy producers) efficiency in individuals who have lost weight. Wait, an increased efficiency, isn’t that a good thing? Not necessarily. In this case our bodies, specifically our mitochondria are becoming more efficient meaning they can do the same amount of work while using less energy. In other words we are using or burning less calories to do the same  amount of work as we did before the weight loss. 

So are we doomed forever? Is it pointless to even try to lose weight? Is it detrimental to lose weight? Not necessarily. Stay tuned for part II when we discuss strategies on how you can successfully lose weight and keep it off for good!
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