The only required macronutrients to sustain life are protein and fats. There are NO essential carbohydrates. I adopted a ketogenic way of eating 12+ years ago. It has corrected multiple health issues, and it has enabled me to remain upright and active.
The basic formula: less than 15% carbs, 40% protein, and 45% fat. My formula is: 3% carbs, 34% protein and 63% fat. This gives me the nutrition I need to remain active and healthy without gaining weight.
I have completed multiple swims using this ketogenic formula, including: an 8-mile reservoir swim, a 10K pool swim in a 50-meter pool, and, for my birthday, 50 100-yard swims on 15 seconds' rest. I plan to attempt 51 150-yard swims in 2025 for my 51st birthday.
While some people are able to consume carbohydrates, too many people consume more than their body should intake. We are designed to eat meat, from the acid level in our stomach to the size of our large intestines, we are meat eaters. Actually, our stomach acid level puts us in the same category as scavengers. Which is more acidic than a lion's stomach, they are carnivore.
If you want to give it a try, give it 90-days. I true 90 days, don't lie to yourself and don't make excuses of why you can't complete the 90 days. If you need/want help holding yourself accountable, I'd love to help. Check out Twiggyfitnessisketo.com for more information.