Alternatives To The Energy Balance Hypothesis
The last article was about the Energy Balance hypothesis for managing body composition, which is the fancy name for calories in VS calories out. Whilst this theory underpins my current approach to body recomposition, there have been times when I thought there might be potentially superior alternatives. There were times I was interested in the role of insulin in fat gain; questioning of all calories being equal; and the idea that somatotypes played a role in determining body recomposition strategies.
Most of this was during my formative years while studying and beginning to somewhat understand the art/science of body recomposition. As I became more acquainted with the science of body composition, a few of these alternative hypotheses made sense - I can see how a little knowledge can be dangerous, particularly when you have not come to terms with context. As I reached the more practical component of my studies and read more research, it became clear that whilst these alternatives sounded good in concept, they did not always stack up stack up in the application and there was little research to support them.
As I gained experience working with clients and slowly became better at critical thinking, my opinion was that based on the current evidence, it was energy balance that controlled body composition. Whilst there are many variables that contribute to energy balance, including insulin, food content and body type, the energy balance hypothesis is the strongest we have for body composition. Until a new theory that is supported by research and logic comes along, it will be the strategy I use in practice.
Alternative One: Insulin - The Fat Storage Hormone
Simplified theory: insulin plays a role in fat storage, therefore we must reduce insulin - primarily through reduced carbohydrate intake - to decrease fat storage.
Insulin has earned itself a bad reputation for doing nothing else than its job, which is to shuttle nutrients into cells for use or storage. The bloodstream likes to maintain a bandwidth for nutrients inside it, so when things get a bit too high - such as after a meal - insulin is released from the pancreas to move these nutrients out of the bloodstream and into cells.
This is a vital function because it allows food to travel through the digestive system, into the bloodstream and then to the cells and tissue that need it. If cells are already full, then nutrients will be transported to other areas to be stored as fat, Body fat is like a savings account that can be mobilised for another day (probably not a rainy day, because we like to sit inside on those days).
This all checks out - insulin stores nutrients and so long as there is space for carbohydrate to be stored in the muscle, it will be. Carbohydrate will only be stored as fat when carbohydrate stores as full.
Insulin inhibits lipolysis
This is where I should have paid more attention in biochemistry to learn more about the interaction between things, not just enough to pass the test. Insulin does inhibit lipolysis in adipocytes and promotes storage of triglycerides, which translates to stopping the breakdown of fat and enouraging storage.
We tend to think that fat storage is bad and fat breakdown is good, particularly for anyone who wants to lose fat. But recall that the role of insulin is to take nutrients from the bloodstream and get them into cells to return blood levels to baseline. It makes sense for insulin to put the brakes on fat breakdown because otherwise, the process of storage would be redundant.
What about insulin resistance?
Insulin resistance is a condition whereby the cells become less sensitive to insulin. Where insulin used to open the gate to let nutrients into the cell, now more insulin is required to have the same effect. It’s a bit like a nightclub - they can be more selective of who comes in when there are plenty of people to choose from. All of a sudden, now your shoes are an issue, even though they were fine last weekend.
The problem with insulin resistance is that because the nutrients are not leaving the bloodstream, their levels cannot return to baseline, which the body does not like. In response, more insulin is released to shuttle the nutrients into cells and reduce nutrients in the bloodstream.
This positive feedback loop only makes the receptors less sensitive to insulin, as there is even more about of it about, which further exacerbates the problem.
Insulin resistance is a real issue, but it’s not a negator to the energy balance hypothesis. Insulin resistance is managed by medication, and nutrition and exercise interventions (training can make the cells more insulin-sensitive). However, this only becomes an issue when someone is insulin resistant, which is often when they are overweight, but it doesn’t necessarily lead to weight gain from the onset
Insulin’s function role is to store nutrients in cells, some of which will be fat cells. If glycogen storage is full, then glucose can be converted to fatty acids and stored in body fat. This is not insulin’s fault - if there was a capacity to store glucose as glycogen that is what would have happened.
Alternative Two: Not All Calories Are Equal
Simplified theory: macronutrients have different impacts on energy intake and energy expenditure, therefore energy intake is redundant.
There is certainly a bit of nuance to this one. In fact, a part of it still influences my current approach.
Let’s start with a common comparison might be 500 calories from avocado vs 500 calories sugar. Firstly, the calories are equal - there are 500 calories in both. What will differ is the composition of the 500 calories - the avocado will contain predominately fat and some protein, alongside a range of micronutrients. The sugar will contain just that, alongside few micronutrients.
If you had to pick one or the other, the avocado is the more nutrient-dense option and contains fat and protein, so it is probably the pick as ‘healthier option’ for the everyday person. The reasoning is what really differentiates these two options are the macronutrient and micronutrient contents of each food. The avocado contains fat and protein, alongside more vitamins and minerals in comparison to the white sugar. So while both foods contain the same energy content, the avocado is considered more nutrient dense.
We typically want to increase the intake of nutrient-dense foods, to ensure that nutrient requirements are being met on a consistent basis. But what most people are really asking when making comparisons is whether 500 calories from each food source is more or less likely to be stored as body fat, or whether its the same? We can only answer this in the context of the rest of the food intake for the day.
At the most basic level, different foods contain different packages of nutrients, which lead to different outcomes in the body. Could you live on just white sugar? No. But I would recommend living on avocado alone either, even though it is more nutrient dense than sugar.
The second component of this theory is the different energy expended to extract energy from the macronutrients. Protein has a thermic effect of food (TEF) of 15-30%, which is much higher than carbohydrate (10-15%) and fat (5%). TEF represents the amount of energy expended to extract energy from the macronutrient, ie. break it down. This amount is often represented a ‘loss’ as if to say the macronutrient loses 15-30% of its potential energy yield in the process of being broken down, which is not the case.
Instead, the body expends the equivalent of 15-30% of the energy yield to extract the full amount from the macronutrient. It is like putting a $1 coin into a machine that spits out $2 coins. You will have a $2 coin in your hands after putting in your dollar, but the financial net gain is $1.
This is an important component of the energy balance hypothesis. Instead of thinking that the food loses energy as it gets digested, we can actually chalk up this amount as energy expended to break it down. Therefore, the net gain is energy intake - energy expenditure, which is consistent with the energy balance hypothesis. While we do need to be aware of the TEF variation of different foods, this fact is not a basis for rejection of the energy balance hypothesis.
Where I still use this process is in the setting of energy and protein targets, particularly for new clients. Because of the relatively high TEF of protein compared to carbohydrate and fat, alterations can have an impact on energy balance. Therefore, we often use a target for both energy and protein intakes, when making and assessing nutritional alterations.
This begs the question - do you have to count calories? The answer is no, but they do not need to be managed. Energy and nutrient targets are extremely beneficial for people looking to establish a new routine, as they provide a framework and guidelines to help adhere to the program. If the same person ate the same amount of food on two days, and only tracked the intake on one, that would make no difference. Counting calories or tracking nutrients is just a method to help people manage their energy intake and make sure it meets their needs.
Alternative Three: Somatotyping
Simplified theory: an individual’s body type can be used to determine the optimal diet for them.
Somatotype is a term used to categorise different human physiques. There are three somatotypes: ectomorph (long and lean); mesomorph (muscular) and endomorph (rotund), and people are ranked in each category. The term was developed by psychologist William Sheldon who attempted to associate somatotype with temperament, as part of a theory called constitutional psychology. While constitutional psychology has been discredited, somatotyping is still used to describe physique.
The tenuous link between somatotyping and body composition went something like this: ectomorphs could easily overtrain and required high energy diets to maintain their weight; endomorphs possibly did not handle carbohydrate intake too well and needed more conditioning to lose weight; and mesomorphs were somewhere in the middle - usually the best of both worlds.
The problem with somatotyping is that it makes a suggestion without first understanding someone's lifestyle. Someone who is lean and skinny (classified as ectomorph) may well be prone to overtraining, but that has more to do with a high training load, which could then also explain why they are lean to begin with. If they stopped training completely, while maintaining their current food intake, this would likely be a different result.
The same goes for endomorphs who are overweight, who might be advised to consume a low-carbohydrate diet because their somatotype does not handle carbohydrates very well. This person may well have low carbohydrate requirements, but maybe it is associated with low levels of physical activity, which could also contribute to being overweight.
The key takeaway is that everyone is unique and have differences that need to be understood to help change their body composition. Grouping people into three categories to determine their body recomposition strategies is too simplistic and lacks the nous required to see what the individual really needs.
Where I Am At Now
I can see why people want to reject the energy balance hypothesis, be it because it has not worked for them or someone wants to be the new expert with all the answers. These are the people who claim ‘everything you know about weight loss is wrong’ before espousing a theory that does not even make sense.
A little while ago I was in a seminar with a high-level performance coach who was sharing his nutritional insights and that he thought the industry ‘had it all wrong’. He advocated a low-carbohydrate diet for athletes and was explaining how glycogen storage works. He stated that athletes don’t need too much carbohydrate, because it if 500g is stored all over the body and then can be released when required for use, that is 2000 kcal of energy they can access during a session. This is sufficient to fuel activity, which was backed up by GPS and load monitoring data.
He missed the part where glycogen cannot be released from the muscles to travel to another site. Once it is stored, it must be used there. This means that the glycogen stored in your legs cannot be released to replenish the arms once they become depleted. Glycogen can be released from the liver, but this is only ~100g - far from the body’s total storage capacity. In essence, this whole theory was underpinned on an incorrect assumption.
That is not to say that my approach is right either. In ten years time, the energy balance hypothesis may well be proven wrong and something superior will take its place. But until then, the work I go with clients will be based on developing strategies to manage their training and nutrition in a manner that is aligned with their energy balance requirements.