T Nation


OK is fat loss caused by simply burning more calories than you take in or not?
If so wouldnt an iso caloric diet yeild the same fat loss results as Ketogenic diets?!?!?!
What causes fat loss? ANYONE?!

As I understand it (and I haven’t read that much about keto diets), the inhanced fat burning is due to your body being in Ketosis (as apposed to glucosis?, I think). Anyway, this means your body is using protein as a energy source (as opposed to carbs) which is a very inefficient mechanism (protein, that is). Hence, you could have the same overall caloric intake, yet your body would have to expend more energy (i.e. calories) in the metabolic process. Further, the keto diet is supposed to reduce muscle atrophy due to the high fat (keeps hormone levels up–relatively) and protein (+ nitrogen balance) content.

Of course, I might not know what I’m talking about, so anyone feel free to correct me.

Fat loss is a bit more complicated than that. There are quite a few factors involved if you are looking to achieve fast and efficient fat loss while keeping muscle loss minimum. First of all your are of course required to reduce your calorie intake with both diets but this depends on how much of a rush you are in, with a ketogenic diet you can actually get away with eating maintenance calories. The basics of both are Isocaloric 1/3 protein 1/3 fat 1/3 carbohydrates ----Ketogenic 25% to 30% protein and all the rest is fat, while this may appear disgusting it really isn’t very bad. Both of these diets are good because they require you to eat more fat which in turn decreases insulin secretion which makes the fat burning pathways more efficient. As for the matter of muscle loss the ketogenic type diet causes less muscle loss than the isocaloric diet. With the isocaloric diet you will be hungrier and weaker for only a short while a few days. With the ketogenic diet you will be weaker for longer, you lungs will burn when working out, and you will tire a bit faster, however shortly after you hit ketosis you will feel rather euphoric. Basicaly the ketogenic diet is better in that it is much more efficient. Ketones are fractured fats, and when you drop into ketosis ketones become the bodies prefered source of fuel, and the real awesome thing about ketones is that what ever isn’t used for energy is excreted in urine and respiration, it cannot be converted back into fat. This information was derived from Dan Duchaines book Body Opus, If you want a top notch diet I recommend you buy this book this guy really knew what he was doing. In this book he shows you his souped up version of ketogenic dieting and walks you through all the steps involved. He truly was a Guru. Hope this helps you out with your questions.

By consuming fewer calories than you expend you get an overall WEIGHT loss, not necessarily FAT loss. Ketosis is a metabolic state where the body uses ketones for fuel. Ketones are produced in the liver from an enzymatic reaction. Triglycerides are first mobilized from the fat cell, make their way to the liver, are broken down into glycerol and fatty acid chains, and then converted to ketones. This enzymatic process is rate limiting, so only a small amount of ketones are produced. Ketones cannot be converted back to triglycerides, meaning it can’t be stored in the body. So ketones must be used immediately by the body or excreted as waste (urinating or breathing; reason for bad breath, ketones oxidize to acetone in the lungs) since ketones lower blood pH, the body protects itself this way. During the period of adaptation to ketosis, about 3 weeks, glucose is still required by the brain. The liver produces this glucose from gluconeogenisis, protein conversion to glucose, if not supplied by the diet. Carbohydrates are considered to be anti-ketogenic and therefore consuming them would not be productive. To lose fat the body must go though this process of converting triglycerides to fatty acids/glycerol. A ketogenic diet favors this because of the extremely low levels of insulin, also anti-ketogenic, and high levels of glucagon, insulin’s opposite. On “conventional” diets, insulin, the storage hormone, is too high to facilitate this process readily. You may get the same overall body weight loss but more is muscle and less is fat.
So to answer your questions directly:

  1. TOTAL WEIGHT loss is caused by burning more calories than consumed.
  2. Theoretically, and generally, you will achieve greater fat loss while sparing more muscle on a ketogenic diet.

    A few things to think about:

  3. You can get fat by ingesting too many calories on a ketogenic diet. It is hard to do so because insulin is VERY low, but possible.
  4. For some reason, the diet doesn’t work for everyone. Many theories for this but I still don’t know.
  5. After adaptation to the diet, ketosis is achieved easier after a carb-up and fat loss seems greater. Probably due to more efficient metabolism caused by up regulation of enzymes.
  6. Be careful carbing-up after adaptation. I seem to have insulin troubles at this time. My blood sugar levels rise way high for a period of time and I seem to experience some type 1 diabetic like effects. Use ALA.
    I hope this is helpful.

Actually, ketosis utilizes primarily FATS, not protein, for an energy source. The fats are less efficient when in ketosis, as you stated, and do not truly yield 9 calories (energy) per gram of fat.