The anti-catabolic effect of proteins is the key to preserve muscles and BMR.
The point is too much of protein will convert to glucose, through the gluconeogenesis effect in the liver, thus kicking out of ketosis the body.
Yet this is not absolute for hard trained athletes who train strenuously during ketosis. Therefore those few extra grams of glucose, made up by this extra protein consumed, will eventually be burned in workouts. Besides protein has dual role to build tissues, so it is more hardly likely to be stored as fat.
In order to enter ketosis, carbohydrate depletion is needed for three to four days, depending on glycogen stores and physical activity.
During this time the organism struggles to switch from carbohydrates into fat burning as fuel. After those 72-96hours, when liver and muscle glycogen stores are empty, liver starts to release ketosomes for energy source.
Breath smells like rotten apple and in urine ketosomes appear, as in blood too.
Under ketosis blood and urine pH drops, since ketosomes are acidic.
As a compensatory mechanism lungs will hyperventilate, in order to counterbalance this metabolic acidosis, by respiratory alkalosis, towards hypocapnia (low CO2).
We have to know that classic keto diet relies firstly on fat (70%) and then on protein.
After all the body adapts in the kind of fuel you are providing to it.
However in bodybuilding protein is the main macronutrient and must be at least 3gr/kg of bodyweight.
In order to give an anabolic kick and escape for a while from ketosis, we can follow the CKD and boost carb intake during the weekend.
In this way insulin will ensure anabolic drive and provide energy to thirsty muscle that are deprived of glycogen stores.
The day after this, training will be of higher intensity, while mental focus will be much better after a short break after a low carb week.
In the absence of carbs, insulin gets low and glucagon, growth hormone high, favoring fat burning. However this project works and is effective under caloric deficit.
The weight reduction is remarkable in the first days, due to water loss from absence of glycogen stores and water.
Later fat is burned as ketosomes are produced from liver.
Fat is burned in a slow pace and one kilogram of adipose tissue requires 9,200 calories for its oxidation.
KDs had pros and cons, as there is a flip side to every coin.
KD was sort of monophagy of fats and proteins, avoiding carbs, while fiber and greens were allowed.
However the saturated fats increase the hepatic synthesis of cholesterol, while cardiology is skeptical to their consumption, since it is still believed to be blamed for atherogenesis and to be inflammatory in the absence of carbs, body loses water and dehydrates, while B complex vitamins and certain minerals are lacking.
Protein elevation under dehydration can strain renal function and elevate creatinine, urea and lower glomerular filtration rate (GFR).
Another thing about low carb diets is the absence of immediate energy release, since carbs and muscle glycogen eclipse.
Slow pace cardio is favored, while explosive anaerobic physical activity is going downhill.
During this time athletes usually use either medium chain triglycerides (MCTs), or exogenous ketosomes that can provide immediate energy source, resembling of simple carbs.
Another disadvantage of KD is that brain metabolism requires 100gr of sugar on daily basis. Therefore ketosomes are alternative fuel, giving the feeling of fatigue mentally and feeling sluggish. We have to understand that mood is bad in the absence of carbs, because carbs promote the release of serotonin, the joy hormone that calms CNS.
So during KD we may feel edgy and grumpy as well, especially in those individuals who are of lower brain serotonin (predisposed to depression).
The benefit of KD is the improvement in insulin sensitivity, in the absence of carbs and the weight reduction coming from fat loss.
Advantages of high carb-low fat diets:
1) Increase in muscle glycogen stores, enhancing explosive anaerobic physical activity (weightlifting, sprinting, lifts, jumps, throws)
2) Improve in mood (anti-depressive effect) by elevating blood sugar and neurotransmitter serotonin (the joy hormone)
3) Promote anabolism through insulin and IGF1 release from pancreas and liver, while carbs are muscle sparing
Disadvantages of high carb-low fat diets:
1) Insulin can lead to fat storage, while organism adjusts not to burn fat, but muscle glycogen instead
2) Lethargy from insulin spikes
3) If poor quality of carbs (refined) are included, then insulin resistance can appear (A1C>5.5%), along with elevated triglycerides and LDL
Advantages of low carb-high fat diets:
1) Improve in insulin sensitivity and reduction in insulin resistance
2) Increase of fat burning, through low insulin, high glucagon and high growth hormone. Basically the system adjusts and adopts in the fuel you provide
3) Ketosomes are known to be muscle sparing
Disadvantages of low carb-high fat diets:
1) Mental focus and sharpness becomes sluggish, since ketosomes are alternative fuels and glucose is primary fuel for optimal brain metabolism
2) If SFAs/trans fats are consumed, then we risk for dyslipidemia and possible atherogenesis that may establish cardiovascular disease
3) Explosive anaerobic physical activity is impaired, because glucose and muscle glycogen lack, the main fuels for strenuous exercise
Moreover insulin and IGF1 are low, meaning there is no anabolism.