I cant imagine a healthy body without some fruit intake (which is carbs) and whole wheat products if I want lets say a shredded wheat for breakfast (however rare or tuna on whole wheat toast). I tend to eat a fair assortment of fruits to the point maybe a little over the top. Im not saying everyone should but I am doing what so far as what beat the family history clock of quad bypasses and diabetes. So far I am ahead of family members by at least 20 years.
A restricted-carb diet makes sense for most people especially those who are physically very inactive or who have metabolic disorders, who are overweight, Type 2 diabetics, and those who have a lot of inflammation. and high LDL cholesterol. A very low-carb diet for prolonged periods is not doable for most people. A no-carb diet, which means cutting out even fiber, would be detrimental in several ways relating to digestion and nutritional deficiencies and could also cause hypoglycemia, fatigue, and loss of muscle mass in many people.
What constitutes a low-carb diet depends on the individual. For most people, I'd say under 75 g of carbs a day is a restricted-carb diet. And those carbs should be mostly from non-starchy whole foods. For someone with a high level of physical activity, laborer, athlete, etc, carbs are necessary as a fuel source and as a means of inducing growth. On a carb-restricted diet, performing hard physical work is difficult due to the quick depletion of glycogen stores.
Nutrition should be tailored to the individual. Two antagonistic metabolic pathways, mTor and AMP must be balanced. mTor is stimulated by anabolic signaling via insulin secretion due to eating, especially by eating frequently and in caloric excess, and by physical exercise. That's how power athletes and bodybuilders gain muscle mass and strength. mTor can be further stimulated with "pancakes" "juice." I' mean PEDs - performance-enhancing drugs like steroids, growth hormones, and such. As many know, eating by itself can require upsizing pants every year. But don't worry, stimulating mTor in excess is life-shortening as the increased cell proliferation that comes with constant growth increases the chances of getting cancer and has other deleterious side effects in the long run.
AMPK is the metabolic process that is activated by fasting (intermittent fasting is sufficient to trigger AMPK), AMPK can induce autophagy during which the body rids itself of defective cells that otherwise might proliferate. AMPK is detrimental to muscle growth and if AMPK is stimulated too much for a prolonged period, muscle loss is inevitable.
It sounds complicated and the involved processes are but achieving cellular homeostasis or balance is not all that hard. Just look in the mirror and make the necessary adjustments. Could be a minor adjustment or it might require massive changes.