Phew, we’ve covered some tough stuff so far, a lot of it looking backwards. Now, let’s look forward. Where do we go from here? What do we do? What numbers are we looking at? What do we need to learn? Are you ready to learn? When will Hobbit stop asking damn questions? :). This is going to be a simplified (within the limits of science) and some of the statements will reflect that. In other words, this isn’t the whole story, but it is the story we need to discuss and in a way that can be easily digested.
Calories in, calories out (CICO because I can’t be typing it out that much): We’ve heard both sides of the argument, either CICO doesn’t matter, or CICO does matter. Who is right? Both, depending on where you are coming from and how you chose to look at CICO. First, let’s look at Law of Thermodynamics and it’s first section, the Law of Conservation of Energy (laws 2 & 3 are about entropy in a closed system and the unavailability of a system’s thermal energy for work as it applies to temperature, respectively) . The first law states “energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another” and goes on to state that there are two energy processes – heat and work, and only those two things can lead to a change in the internal energy of a system. The argument against CICO is the human body is not a closed, isolated system that is never in equilibrium (energy in and out is constant). That is correct, the human body is never in equilibrium, unlike, say your car. Your car is either running or not running. Energy from gas and air is converted to heat and movement, and while the heat will not dissipate at the same rate as you are moving down the road, all the energy lost as heat plus the energy used to move the car can be measured and will match the energy from the gas and air used. But, we are not a Honda Accord. We are HOOMAN! So if you look at that argument at the most basic value, they are correct. 2000kcal from food will not result in 2000kcal of movement or heat energy created by us. The work value and movement value from the calories is not equal.
But, once you step outside of that very basic, blanket look at things, CICO does work. You need to take into consideration a variety of factors:
1) Not all dietary calories are used by the body in the same manner. There’s different metabolic pathways, different oxidation (conversion into energy) of the calories, and they are used for different things in the body.
2) We – as in our body – are not the only organism using the calories from the food we eat. What? Actually, we don’t even eat our food, bacteria in our digestive system does, which then converts it into substances our body can use. Those bacteria by breaking down our foods convert energy, and not all that energy is converted to things we can process – like insoluble fiber and resistant starch.
3) Your metabolism and what is called The Hall Principle, which surmises that a) the body is in a constant imbalance of energy in\out, the metabolism is in a constant state of change, and that dietary calories are not precise.
4) Hormonal and immune system interventions play a factor.
5) Imprecise measurement of “fat usage.”
I happen to agree with all of this. Let’s break these down. In order to counter the original argument, we need to look at where it started. The theoretical energy stored in 1 pound of body fat was determined to be 3500 calories. So, if you ate nothing and used enough energy in movement to go through 3500 calories, then you would lose a pound of fat, which when tested in the real world, didn’t happen. Why?
1) Your body doesn’t run off just fatty acids. Yes, it uses these for energy in a variety of ways, but it also uses amino acids (proteins) for energy – specifically muscle glycogen and in the production of ketones- and not all fatty acids are used at the same rate. Fatty acids used for the production of ketones (along with some amino acids) for fuel, yes, but the are also used at a significantly different rate for skin, hair, and other cells.
2) Your body – and associated bacteria and organisms in it – can take up to 36 hours to digest your last meal. So, while you are “burning 3500kcal of body fat” you are still adding energy to your body. Obviously, if you are adding in while taking out, the numbers are not going to be accurate.
3) See #2. And to expand on that, your metabolism will adjust energy creation based off available energy – either stored or circulating – and change the rate at which it uses, replenishes, and stores energy. Your use of energy isn’t constant, either. If you run a mile, the rate at which you are moving your muscles, the length of your stride, and the rate that you are moving is never consistent. It can be averaged, yes, but it still will be imprecise. Lastly, for this part, your food’s calories are not precise. They are an estimate based off dietary studies. While they are close, from one lot to another there is the possibility of several percent difference between what actual calorie level of energy you will get from your food. This is even less precise when it comes to animal products. Look at the ribeyes in your local grocery store. While the USDA says that a “ribeye” has 152 calories in 4oz with 5g fat and 25.5g protein, you have to ask, did anyone talk to the cow about that? I’ve seen ribeye with huge slabs of fat around it and marbled like the floor of the Sistine Chapel, and I’ve seen ribeyes that are rather lean, not much marbling, and just a little thin strip of fat. The calories per oz cannot be the same. Therefore, the amount of calories you are eating is a ROUGH ESTIMATE and not precision.
4, 5) Fat loss doesn’t automatically equate to weight lost, or even size loss (you know, around the belly and stuff 🙂 ). Water balance, hormonal imbalance\changes, inflammation all play a role in your size and mass. You can add muscles without losing weight. You can lose muscles without losing weight. You can not gain fat, not gain muscles, and gain weight. You can not gain fat, not gain muscles, lose weight.
So great Hobbit, that wasn’t helpful. You’re telling me that calories matter but they don’t mean I’m going to lose my fat! Well, yes and no. Calories do matter, but more importantly, what calories you are using, how you are using them, and the rate you are using them is what really matters. Let’s break the macronutrients down, just the macros, we aren’t going to get into the micronutrients like vitamins and minerals that might come along for the ride.
Carbohydrates: You will hear “simple sugars” and “complex sugars” tossed around a lot. In a nutshell, simple carbs are your basic sugars like you would get from a can of Coke, a Snickers, or dumping in your coffee. These metabolize quickly to be used for energy. Complex sugars are long-chain carbs that take longer to process into glucose, like from wheat flour, some fibers, starches, and fruits. Regardless of the source, carbs get converted to glucose and then to fuel.
Protein: Proteins – amino acids – are used primarily for cell structure, and can be used with fatty acids (fats) to build ketones for fuel. Also, a percentage of amino acids are used for muscle glycogen (fuel) and is stored for muscle energy. Protein doesn’t get stored in fat. Protein – except for rare cases – does not get converted to blood glucose. These rare cases are things like a metabolic disorder or a time of crisis where there is not sufficient other sources of fuel to use. The body will exhaust other sources before it starts using dietary protein, then it will break down amino acids from cells. We don’t want that. Nope. Excess dietary protein is broken down by the kidneys and released in urine. If you are eating more protein than you need, it won’t hurt you. It won’t help you, either. The key is to use it :). We will get to that later.
Fat: Fatty acids have multiple uses in the body. They are used for cell growth and repair. They are used in fat cells for storage of energy, they are used in fat cells for organ and skeletal protection from trauma. They are used for fuel – not only in the production of ketones, but certain organs prefer fatty acids over glucose, the major one being the heart. You need a certain amount of fat intake in your diet to make sure that the body doesn’t scavenge protein to use for fuel, that number is universally recognized as .39g of fat per lean body mass. This is under normal circumstances, in time of trauma or illness, this can increase. When it comes to using fuel, the body will use carbs first, then fat, then protein. If you are eating enough carbs to run stuff, and more fat than you need, the body will store the excess fat. As fat. This why you will never see a High Carb, High Fat diet recommended. It is either HC\LF, or LC\HF. Part of the reason that “fat is bad” got to be a thing is eating a lot of fat with the Standard Western Diet which is high in carbohydrates causes obesity. On the flip side of that, the high amount of carbs in the SWD can lead to insulin resistance because of the presence of too much fat. That, and carbs are not a constant source of fuel, it can wildly swing in either direction, causing a feeling of being tired, brain fog, anxiety, hormonal imbalances, and all that other stuff we as keto people are trying to avoid.
In the name of complete transparency, I tried a HC\LF diet for a year. It worked for fat lose. It didn’t help with lean mass. It raised hell with my mental clarity and sleep patterns, but I had constant energy.
In the next part, we will talk about how to take what we learned today and combine it with what we will learn about how the body uses these calories to get us into a ballpark of how we should structure our plan. Love yourself. Be good to yourself. Forgive yourself. Trust yourself.