It seems to be common wisdom that having carbs as the main calorie source is important, and while I do share that, I want to understand why exactly.
I wouldn’t want to oversimplify an issue I am not an expert on, but, if calories are calories, does it really matter whether your main source of them comes from either of the two? What would the consequences of having fats as the main calories be? I presume that question has to do with metabolism; perhaps fats metabolize slower and, as such, we would feel low on energy?
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Really looking forward to getting to know more about this :)
Sugars & starches are absorbed by the gut as glucose, fructose, and galactose which are consumed by cells for energy; there is nothing that needs to happen inside the body once these have been absorbed they are available as energy.
Fats are digested to a bunch of different products and there remains uncertainty if some of those are absorbed (EG cholesterol esters, humans have the right enzymes present for hydrolysis but not clear if we actually digest them or not). Some of those products cannot be used for energy (you will just pee them out) while others can (via gluconeogenesis) but it’s a less efficient process then with carbs so your body will prefer not to do that and just store all fat calories as fatty tissue if needs are met via carbs. Most of the fat products don’t serve a primary purpose as energy, they have other uses in the body.
Proteins are digested to aminos and peptides which the body uses for protein synthesis. Peptides will be broken down into aminos if they are not used for synthesis. Some aminos can be converted to glucose (again via gluconeogenesis) while others cannot (peed out or converted to ketones) but the body really doesn’t like doing this as the gluconeogenesis pathway for aminos is extremely inefficient and generates harmful byproducts, you have to be essentially starving for the body to choose this over just converting them into fatty acids and then storing them.
Sugars & starches are the only micros where 100% of the calories are energy. This doesn’t mean you should try and figure out what your ratio is and eat more fat/protein because some is peed out, even in an individual it varies wildly throughout the day so its still calories in - calories out. Carbs are where our energy comes from and the other macros have to be converted in to carb digestion products to be used as energy.
It isn’t. While carbs are the more efficient energy source, any excess is stored as body fat, same as excess energy from dietary protein and fat.
There are certain exercises and movements where you’d want to have glycogen available - explosive movements like sprinting, jumping, some weightlifting, - and not having glycogen would impact performance.
But carbs are the one macro that are not essential, as our bodies can synthesize all that we need from fat stores.
A calorie is a calorie is an oversimplification and inaccurate. It’s mostly correct from a pure energy standpoint, but there are essential proteins and fats that we MUST ingest to function properly. Saying that a calorie is a calorie ignores the fact that we have structural & chemical requirements as well as energy requirements.
Carbs for energy/glycogen.
Not sure about general population, but, for those resistant training carbs are ideal.
Just look at bodybuilders and strength athletes.
Most of their macros are carb dominant.
There are plenty of folks out there who don’t get the majority of calories from carbs. You absolutely do not need to get more calories from carbs than from fat. Just look at the people who follow a carnivore or keto diet. They all are eating low carb.
But to answer your question most people who eat a high carb diet are bodybuilders and folks who are extremely active who are constantly depleting their glycogen stores. However there is absolutely No need to eat all those carbs unless you are trying to bulk up. Fat is much more important for overall health and wellness being.
Resistant Training I utilize carbohydrates because they’re great for energy and power and it gives me a great fulfilling workout. I’ll make a sweet potato hash with eggs, or have a bowl of oatmeal an hour before lifting. I generally try to limit my carbs throughout the day and consume higher fats and protein. As another poster mentioned, carbs raise your blood sugar as well as your insulin levels, which ultimately if you do it enough will lead to metabolic syndrome. That leads to a cascade of health issues.
You can live without carbs, but you cant without protein and fats.
Its not important, generally disadvised to have your calories from carbs. Its causing a lot of issues [non-alcoholic fatty liver, insulin resistance, type2 diabetes etc etc etc].
Those are because of the outdated (and often biased)studies showing fat is bad I don’t think a high carb diet is unhealthy either but a high fat diet is also healthy if you enjoy it
I would recommend checking out r/keto or r/lowcarb
Carbohydrates provide quick energy and its also the only source of energy your brain can really use. At minimum, our brains require about 135 g/day. For athletes and anyone that exercises, carbohydrates are important because our muscles use it for movement.
Fats are used for energy throughout the day and when we are fasting (between meals, sleepong, etc). Our bodies can’t use fat directly. It has to break it down into glucose to be able to use it. That’s why it doesn’t immediately spike blood sugar. (HOWEVER this doesn’t mean fats are a safe food for insulin resistance. Overconsumption in general, whether fats or carbs can increase fat stores in cells which can make it hard for insulin to bind to cells, hence “insulin resistance”). The concern for eating too much fat is consuming too much saturated fat, which can cause cardiovascular disease. There’s definitely some variability to this though, some people can tolerate more fats than others and it can depend on your family history.
Carbohydrates are considered the “major source of energy” because they’re typically more nutrient dense. Vegetables, fruits, whole grains which have vitamins, minerals, and fiber are mostly carbohydrates. We want most of our calories to come from these foods for this reason. Fats, while important for many things in our body, often can’t provide all these nutrients.
So carbs and fats are utilized as energy, believe it or not you burn fat while sitting around all day. (This is why it’s important to build muscle so your body has a higher basal metabolic rate).
What people here haven’t mentioned is the calories per gram. Fats are 9 calories per gram while carbohydrates are 4 calories per gram (protein is also 4 calories per gram). This is important because if you have high fat in a day, you’ll end up adding a lot of calories, maybe unwanted, into your diet. I’m not saying fat is bad but having a control of the amount you’re having is important.
The reason why you should have more calories from carbs is because they are utilized when you workout, you’ll have more energy to perform exercises and such. Without carbs you’ll feel a bit off and sluggish
Carbohydrates are main source of energy. Fats in high amount could raise trigylicerides, blood pressure… Biggest part of macronutrients should be carbohydrates (complex and simple carbohydrates from fruit), as they are not harmful in such amount.