Nutrient classification

Daily requirements for macronutrients measured in grams, and micronutrient requirements measured in milligrams and micrograms； In addition, in recent years, the field of functional nutrition has gradually included physiologically active dietary ingredients such as phytochemicals into the broad nutrient classification system.

The "three macronutrients" we often refer to as carbohydrates, protein, and fat are the most familiar knowledge points for fitness enthusiasts and people who want to lose weight. The first thing that pops up when many people open the food recording APP on their mobile phones is the intake progress bar of these three - Oh, by the way, many people tend to leak water. In fact, water is also a macronutrient. The human body needs at least 1.5L per day, accounting for 60%-70% of the body weight. I used to help a client who was losing weight adjust her diet. Her other indicators were well controlled, except for constant constipation and slow weight loss. Later, when I asked, I found out that she only drinks 500ml of water a day. After filling up on enough water, things went smoothly within a week, and her weight loss speed returned. There are also differences in the classification of macros, such as dietary fiber. In the past, many domestic nutrition textbooks would list it separately, but now it is more classified as "indigestible carbohydrates." The USDA's 2020-2025 Dietary Guidelines also specifically label "added sugars, dietary fiber, and total carbohydrates" separately as recommended amounts. To put it bluntly, it is to make it easier for ordinary people to adjust their diets without having to dig into the definitions. Speaking of which, when I first joined the industry, I argued with my colleagues for half an hour over whether dietary fiber counts as carbohydrates or is a separate category. Later, after reading the dietary guidelines of several countries, I discovered that they didn’t bother with definitions when classifying them. They were all about making it easier for people to understand.

After talking about macronutrients that have a strong presence, let’s talk about micronutrients, which are like memorizing the periodic table of chemicals every time I mention them—that is, vitamins and minerals. You usually hear that vitamin C prevents colds, iron supplementation improves anemia, and calcium supplementation promotes bone development. These are all things like this. How small are they needed? For example, adults need 100mg of vitamin C per day, which is equivalent to 1/10 of a gram. The total amount of all the micronutrients you supplement in a day would not weigh as much as a 10g scoop of protein powder. There are also many differences in the classification of this area. Substances such as choline and inositol were previously classified as "vitamins" and not considered essential nutrients. In 2016, when my country updated the "Reference Intake of Dietary Nutrients for Chinese Residents", choline was officially included in the B vitamins. Regarding the recommended sequence of nutrients, many functional nutrition scholars now advocate that ingredients such as taurine and L-carnitine should also be classified as micronutrients. Traditional academic circles believe that only those whose deficiency will cause clear deficiency diseases are considered. The two sides have been arguing for several years without reaching a conclusion.

To use an analogy, macronutrients are like the steel bars, cement, and bricks used to build a house. They are the foundation that supports the entire building structure and daily operations.； Micronutrients are like nails, screws, and waterproof glue. If they are in small amounts, if any one of them is missing, leaks will easily occur. ； And now more and more people are talking about "phytochemicals", just like the fresh air system and water purifier you install in your house. They are not strictly necessary, but after installing them, living in them is obviously more comfortable and the probability of problems is much lower. For example, anthocyanins in blueberries, lycopene in tomatoes, isoflavones in soybeans, as well as resveratrol and curcumin, which are very popular in health care products circles, all fall into this category. I used to make dietary plans for elderly clients with atherosclerosis. Instead of just asking them to take health supplements, I just added 200g of steamed tomatoes every day. After three months of reexamination, most people's blood lipid indicators have slightly improved. There is no clear "deficiency disease" of these ingredients, but long-term intake can indeed reduce the risk of chronic diseases. Of course, this area is more controversial. The traditional nutrition community has always believed that these types of ingredients can only be regarded as "dietary functional ingredients" and are not worthy of being called nutrients. After all, even if you don't eat tomatoes for your whole life, you will not get any specific diseases. However, most practitioners of the functional nutrition school believe that the current problem is not nutritional deficiencies caused by insufficient food, but nutritional imbalances caused by eating incorrectly. Incorporating such ingredients into the classification system is more suitable for today's dietary guidance needs.

In fact, I have been doing nutrition consulting for so many years, and I have never stuck with clients on classification definitions. I just use different classification logic for different scenarios: If you are working out to gain muscle and lose fat, just keep an eye on the proportions of the three major macronutrients.； If there are pregnant women or children at home, you must find out the appropriate intake of vitamins and minerals. ； If you have chronic disease management needs, it never hurts to learn more about the effects of phytochemicals. To put it bluntly, classifications are artificially drawn. If they can help you eat healthier, they are good classifications.