The Health Series: Nutrition Part 2 - The Basics, starting with Macronutrients
Hello friends, this is Babae!
Last week, we looked into the history of the USDA, the Dietary Guide, and how Big Agriculture (Big Ag) influence studies and research, which in turn influence national policies and, ultimately, our lives. It does not matter that you do not live in the United States. Neither do I. I live in Vancouver, BC, Canada. The happenstance of Big Ag's influence on your country's policies is the same because, friends, we live in a globalized world.
I left off with the latest Canadian Food Guide 2020, which I will recap:
- Have plenty of vegetables and fruits
- Choose whole grain foods
- Eat protein foods
- Make water your drink of choice
Notice that, as I have said, there are no food groups or servings suggestion and that this suggests that there is more than one way to fulfill our nutrition needs, and that different people may reach the same health goals with different portions.
Some of you may think I am reading too much into it, but my interpretation of the food guide is to eat plant-based. There are many reasons for this, as I will explain in this article, but if you do not agree with my interpretation, you can draw your conclusions.
In 2007, the previous Canadian Food Guide release, there were four food groups: vegetables and fruits, grains, milk and milk products, and meat and alternatives. The elimination of the food groups suggests that you can get all the nutrition you need from one, or a combination of the previously defined food groups. The question becomes: which food group, or which combination?
Let's look at some of the basics.
We know that we can get energy from one of three sources called macronutrient: carbohydrate, protein, and fat. Each of these energy sources give us a specified amount of energy. Energy is measured in Calories. Notice this captialized "C". A Calorie is equivalent to a kilocalorie (kcal). The reason for the difference is that the lower-cased calorie is the amount of energy to raise the temperature of one gram of water by one degree celsius, where the upper-cased Calorie is the amount of energy to raise one kilogram (one thousand gram) of water by one degree celsius. So one thousand calorie is one kilocalorie, or one Calorie. If your country measures energy by Joules, then one Calorie equals to 4.18 kJ for your conversion. In my opinion, if a country is measuring energy from food in Joules, it is counter-productive for its citizen as most of the world's research uses Calorie.
One gram of protein or carbohydrate provides four Calories, while one gram of fat provides nine Calories. This leads to the concept of caloric density, which I will address later in this post.
Other than for energy, macronutrients are required for the proper functioning of your body. Carbohydrate breaks down to glucose, which is your body's main energy source as it is most readily available to use. Fat protects you, your organs, and your cells' membrane. It also stores energy, which is why this is the second place your body will look to when it needs energy. Protein is the building blocks that your body uses to grow and repair tissues, including your muscles, which you may have heard of it referred to as lean body mass.
To understand this from an energy stand point, lets look at this analogy: carbohydrates are the firewood; fats are the furniture; and protein is your house. When you need to light up your fireplace for heat, you first use the firewood as its readily available, and that's its purpose. When you don't have any firewood available, you start burning a table or a chair. When you have no more furniture to burn, you will have to start taking apart the house and maybe burn the door or window. As you can imagine, its not preferable for your body to use protein, or breaking down tissues for energy if there are other options.
Your brain interprets hormones in your body. Interesting fact: your body does not have oxygen senors but carbon-dioxide sensors, meaning that the trigger for you to breathe is not the lack or oxygen, but the surplus of carbon-dioxide that it needs to expel. In the same manner, your body does not know when you are full, but will know when you are hungry.
Your body secretes ghrelin when you are hungry, and in turn increase your dopamine. Dopamine is a reward mechanism, so therefore you will seek the reward of food when you are hungry. When you eat, your stomache stretches, which stops of secretion of ghrelin, and secrete seretonin. Seretonin suppresses dopamine and you stop seeking to eat.
I briefly mentioned in the previous post that glucose triggers insulin release, which makes your fat cells release leptin. Leptin suppresses the feeling of hunger. We know that most carbohydrates break down into glucose by the body, so eating carbohydrate is another way for us to feel full.
Combined, stretching the stomache to stop the secretion of ghrelin, and eating carbohydrates to trigger insulin make us feel full.
Now, let's look at the previously defined four food groups: vegetables and fruits, grains, milk and milk products, and meat and alternatives.
What we know is that vegetables and fruits will provide us with mostly carbohydrate, and some protein and fat; grains provide mostly carbohydrate and fat, and some protein; milk, meat and alternatives provide mostly protein, and some fat and carbohydrate. What this means is that you can eat from a single food group and still get all three macronutrients.
The question becomes: how much of each should you have?
The short answer is: it does not matter because energy is energy!
This is partially why you can survive on any of the trending diets. You will survive if you eat. Staying healthy, including losing weight, is a different matter.
I will briefly introduce three of these diets as these are the most popular and enduring. Like I said, there are so many diet trends (fads) that come and go, it's hard to keep up.
- The Ketogenic diet is low-carb and high-fat. The hypothesis is that, by lowering carbohydrate intake, after the glucose from the carbohydrate in the body has been depleted, the body will go into ketosis, which is the metabolic state where your body burns fat for energy. Ketosis has been proven to retain lean mass while the body burns the fat. What was misunderstood and has been clarified by recent science is that the biggest gains happen when the body comes out of ketosis and not while in ketosis itself. Coming out of ketosis, the body replace damaged cells with new cells, and you get feel more focused and energized.
- The Atkins diet is very similar to the Ketogenic diet but instead of being focused on fat, it encourages high protein intake as well. So this is a low-carb, high-fat, and high-protein diet. Protein is known to have a higher thermic effect of food (TEF), which means that it requires more energy to digest, absorb, and dispose. This will in turn increase your metabolism for the duration of digestion and shortly after. The body will also secrete peptide YY, a hormone that makes you feel full. The full picture looks like this: you intake less food overall because protein makes you feel full, so proportionally, you intake less fat, which is calorically dense. The lower calorie intake combined with the higher metabolism from the TEF of protein promote a good calorie balance.
- The paleo diet does not favor any of the three macronutrients. Instead, the premise is that human biology has not evolved fast enough to keep up with the enviornment and so that we should eat more like our ancestors: vegetables, fruits, nuts and seeds, and lean meat and fish. The key is not what it prescribes to eat but what it restricts you from: grains, dairy, legumes, refined sugars, salt, and processed foods. I think it is common sense that it is better for our health to avoid those processed foods, which inherently contains high levels of salt and sugar, in any diet. The human body is very adaptive, and so is its digestive system. Our microbiomes start changing after the first meal when we change our diet. The effects, however, won't be seen for at least a week. As for the prescription of avoiding grains and dairy, I will cover that in a later post when I discuss some of the concerns and misinformation on the Internet.
When you have a basic knowledge of how the body works and what effects the macronutrients have on your body, it is really not difficult to create your own diet, as many people on the Internet have.
As a recap of the diets above, you should:
- Eat more protein as it makes you feel full so you eat less, and have higher TEF so you sustain a higher metabolism
- Eat less or eliminate refined sugars, salt, and processed foods
- Eat less of the foods your body disagree with
- Get into and out of ketosis
"What? Get into and out of ketosis?"
Yes, you can control when you get into and out of ketosis. It is called time-restricted feeding, or intermittent fasting. We will discuss this next week.