How Much Protein Do You Need on A Lower Carb Diet?

I've replaced my admittedly confusing web page about how to calculate your protein needs on a low carb diet which is found on my Low Carb Facts and Figures site with a new automatic on-line calculator. So now you can easily figure out how much protein you need to eat on your own low carb diet based on your own daily carb intake, your weight, and how long you have been eating a low carb diet.

The assumptions on which it is based are documented on the calculator pages. They are drawn from the research Lyle MacDonald published years ago in his book, The Ketogenic Diet.

You can try out the calculator HERE

The most important thing I learned from Lyle's book is something few nutritionists seem to understand. While it is true that the brain needs some glucose to run properly, since unlike all the other organs in the body it cannot run entirely on ketones or free fatty acids, 58% of the protein grams you eat can be converted into glucose in the liver. So there is no need to eat any carbohydrate at all.

But even more importantly, as Lyle documents in his book, after three weeks in a ketogenic state, the brain adapts and needs much less glucose than before. So while it is true that you need about 100 grams of glucose when you start eating a ketogenic low carb diet--one that provides less than 100 grams of carbohydrate a day--after three weeks on a ketogenic diet your brain needs only 40 grams of glucose.

Dr. Bernstein advises in his book that if you are eating his 6-12-12 grams of carb per meal regimen and are not losing weight, you should cut your protein intake. This should only be done after you have been on the diet long enough to have dropped your protein need, and you are trying this approach do double check that the amount of protein you are eating is enough to keep your muscles repaired.

If you are not eating a ketogenic diet, you will need about 100 grams of glucose to run your brain. You can use the calculator to calculate your protein need in that case, just select that length of diet option for "less than 3 weeks" on a low carb diet.