Conventional wisdom tells us that we get fat because we either eat too much food or exercise too little. Put another way, the number of calories we consume is more than the number we burn. The problem with this oversimplified explanation is that it does not tell us how we get fat. Gary Taubes, author of Good Calories, Bad Calories,1 says that we should not look at calories in versus calories out for an answer to this question. (For a detailed myth-busting of calories, see Part Two of this book.) So, what should we be looking at?
When you hear Gary Taubes explain why we get fat, you soon realise that for the past however many years we’ve been fooled by many health authorities. It’s never been about how much or how little we eat, says Taubes – it’s always been about what makes our fat cells bigger or smaller. ‘Obesity is a disorder of excess fat accumulation, not energy balance, not overeating, not a sedentary lifestyle,’ he says.2 ‘Overeating and inactivity are compensatory effects, they are not causes … We don’t get fat because we overeat, we overeat because our fat tissue is accumulating excess fat.’ What Taubes is saying is that we start to overeat because we are getting fatter, and not the other way around. So, what causes this fat accumulation, what regulates it, and how can we manage or control it? It seems that once you know how to get the process of fat accumulation under control, you will be able to burn body fat effectively, lose excess fat and live a happier, healthier lifestyle.
Let’s look briefly at how fat works within our body and how it is stored. Free fatty acids travel around our bloodstream supplying us with fuel. They also move in and out of our fat cells, but once inside the fat cells, these fatty acids bind together to form triglycerides, or fat. Triglycerides can only be formed within fat cells, not outside. Gary Taubes likens the process of triglyceride formation to buying a big item of furniture. When it’s delivered, you realise that it doesn’t fit through the front door, so you have to take it apart and then reassemble it inside the house. This is how this process works: fat enters and exits the ‘house’ (fat cell) as free fatty acids, but once inside the house, they bind together to form triglycerides. Furthermore, ‘inside the fat cell, fatty acids continually cycle into triglycerides and back out again’. Fatty acids are not meant to stay permanently inside the fat cells.
When do we get fat?
We get fat when more fatty acids enter our fat cells than exit them. As the ‘house’ gets more and more crowded, so it is forced to expand and you get bigger and fatter!
The converse is also true. We get leaner when more fatty acids leave the fat cells. The only way you can ensure that this happens is to make sure that the ‘thing’ that regulates this process is well managed.
So, what regulates this process?
The hormone insulin puts fatty acids into fat cells, so you could say that insulin drives fat storage. When insulin levels in our bodies are chronically elevated, fat accumulates in our fat cells. When insulin levels drop, fatty acids escape from our fat cells and our fat deposits shrink.
Okay, so now we know that insulin drives fat storage, but how can we control our insulin levels – or, more importantly, how can we keep our insulin levels down? To answer this question, we have to look at what drives insulin production.
The answer: two macronutrients – carbohydrates and protein.
Carbohydrates and proteins are what we call insulinogenic, i.e. they stimulate the production of insulin. The more carbohydrates you eat, the higher your insulin levels will be. And because carbohydrates have no satisfying properties, you end up eating more of them. Let’s look at an example. How often have you eaten a bowl of cereal for breakfast and felt hungry again an hour and a half later? The reason for this is that the carbohydrates in the cereal provided you with a short burst of energy, but just as quickly that energy dissipated and left you feeling hungry again. What did you do next? You ate again, maybe this time a slice of bread. But the bread had the same effect as the cereal: it only kept you full for a short while and then you felt hungry all over again. And reached for another slice of bread … It’s a vicious cycle, and the problem is that every time you eat those carbohydrates, your insulin levels go up and up and more and more fat enters your fat cells instead of leaving them.
The other driver of insulin is protein. If you consume too much protein, and especially those that have a higher insulinogenic effect, such as whey protein and milk, your insulin levels will rise. But if you consume too little protein, protein synthesis will not occur properly and the small amount you did consume will become nothing but extra calories.3
We now know why we get fat and what drives insulin – ‘[c]arbohydrate [and protein] is driving insulin is driving fat’4 – but what can we do about it? It all comes down to the quantity and quality of food you eat.
First of all, you need to ensure that you get your quantities right. Many new Banters mistakenly think that Banting is an ‘eat as much as you like’ lifestyle or that they can ‘eat freely from the green list’. This is untrue. Please do not fall into this trap! Remember the mantras ‘Everything in moderation’ and ‘Too much of a good thing is not a good thing’. The LCHF/Banting lifestyle is about eating when you are hungry and eating until you are satisfied. Unfortunately, not everyone knows when they are truly hungry or when enough is enough! We’ll make this easier for you to understand when we explain macronutrient quantities in the next chapter. Right now all you need to understand is that Banting is a diet high in fats, moderate in proteins and low in carbohydrates. You will need to make sure that your protein intake per day is as close to spot-on as possible (more on this later); that you lower your carbohydrate intake, but not exclude carbohydrates completely because, if you do, you will miss out on nutrient-dense vegetables, and this in itself is a recipe for nutrient-deficiency disaster; and, finally, that you accept that fat is not your enemy and never was. Fat can be eaten in greater amounts, BUT, as with everything, there is a limit to the amount of fat you should be eating depending on where you are in your weight-loss journey. But don’t stress, we explain this in greater detail in the next chapter.
Know that the food you choose to eat will determine your weight-loss success. If you have a metabolic disease5 and you choose to eat foods that drive up your insulin levels, then you need to be prepared to carry the consequences. If, however, you want to lose weight and live a healthier life by choosing foods that have a lower insulinogenic effect, we have made life infinitely easier for you by highlighting those foods on the green list with a low-insulinogenic, nutrient-dense (LIND) value (see Part Three for an explanation of the Green, Orange and Red food lists). Note that if you do suffer from a metabolic disease, you should only eat from the green list – you don’t have to eat only LIND foods, but if you really want to improve your health, you should consider them your friends. If you’re one of the lucky ones and don’t have a metabolic disease or are more carb tolerant than most, then you can eat from both the green and orange lists with pleasure. But take note that when we talk about orange foods, we are really only referring to vegetables and berries. If you want to eat any of the other sugary fruits, then rather see them as sweet treats for once in a blue moon.