Carbohydrates and Why We Need Them

For a good chunk of the general population, especially those who have low activity levels and inactive lifestyles. Once calories, protein, and fiber are matched the ratios and amounts of carbs and fats isn’t going to matter much [4].

But if you’re active, train with moderate to high volumes, care about performance, seek optimal outcomes and just want to know ‘a better way’. It’s undeniable that once the measly amount of fat required for optimal function is met, you’re pretty much going to want to cram in as many carbohydrates as your calorie allotments and energy requirements will allow.

Even the argument for carbs over fats in general, across the board, is very robust. Here is why…

1. Before I mentioned once calories, protein and fiber are matched it doesn’t matter a lot. Well, the fiber part of that is certainly far more easily achieved if you’re eating plenty of carbs. Basically, we require 15-18g of fiber per 1000 Kcal consumed, and 80% of that is to be from plants (ISSN position stand)… Well, plants are almost always completely carbs, and fiber is… carbs. So going low carb is just making your ability to eat enough fiber harder for no justifiable reason.

2. Carbohydrates contain 4 Calories per gram. With corresponding carbohydrate dense foods typically presenting themselves in the form of filling, fibrous fruits, vegetables and whole grains that provide a great deal of food volume, for not a lot calories. Think of this as ‘Calories per bite’, ‘Calories per gram of food’, or ‘fewer Calories for more surface area of food’. More food volume creates a greater stretch of the stomach providing the brain with a more powerful signal of fullness. Fats are 9 Calories per gram and typically come in the form of lower fiber easily consumable foods like oils, and even a small amount of them yields a lot of Calories. Satiety or fullness is consistently more closely tied with Calorie density, fiber content, and food volume [2,3] as opposed to the myth that the carbohydrate and fat content of food is the primary influence, due to the blood sugar response that follows consumption [5].

3. Carbohydrates (glucose) is the bodies preferred fuel source for all cellular metabolism, undeniable. Fatty acids are only able to be utilised by the body as a backup fuel source in the event of insufficient glucose availability. If glucose is present, the body will preferentially use glucose for good reason. For the body, to utilise fatty acids as it’s a primary fuel source, a bunch of annoying metabolic crap needs to happen to create Acetyl CoA for the kreb cycle. The process of pyruvate from carbs, to acetyl CoA, is far more straight forward and 'easier'.

4. If you lift weights it’s very clear you’ll more likely perform your best if you have sufficient carbohydrate available. The intensity and duration of strength and muscle growth (hypertrophy) specific training is glycolytic in nature. Meaning primary fuel for the activity in reference is glucose (carbs). Carbs provide the fuel that will best facilitate optimal training performance for this type of training, undeniable.

5. If your sport involves longer low-intensity bouts, fatty acids predominance at best performs the same as having higher carb availability in the research. While there may be some utility in doing some training in low carbohydrate states to generate greater training adaptations [1]. When it comes to competition time or performing your best, a crap of carbs is certainly the best idea.

6. In point three I mentioned the body has to go through a bunch of metabolic 'things' it would rather not do to create acetyl CoA from fatty acids. The body doesn’t like doing this because it’s inefficient. Not only that, but the kreb cycle is rate limited by the availability of oxaloacetate which is a by-product of carbohydrate metabolism. Thus, the kreb cycle will run optimally and best if the diet is sufficient in carbs. Once you understand what’s going on ‘under the hood’ you’ll realise that at a cellular level. Carbs just make way more sense. For sports/training performance, fat loss, general health, and muscle growth. Carbs win over fats, especially when you understand the physiology behind it all.

[1] https://www.ncbi.nlm.nih.gov/pubmed/21660838

[2] https://www.researchgate.net/publication/15701207_A_Satiety_Index_of_common_foods

[3] https://www.ncbi.nlm.nih.gov/pubmed/9032702

[4] https://www.ncbi.nlm.nih.gov/pubmed/25182101

[5] https://www.ncbi.nlm.nih.gov/pubmed/17524176