How many ketones you produce is dictated more so by how much sugar is available for fuel. The macronutrients you consume dictate ketone production to a larger extent than calorie consumption. For example, even if you were eating a ridiculous amount of calories, your body would still produce ketones if your carb consumption was low enough (and protein intake wasn’t ridiculously high).

When we consume net carbs, it shifts the balance of certain substrates in the liver (i.e., by increasing oxaloacetate levels) to the point that ketogenesis does not occur. This feedback mechanism occurs because sugar is our primary fuel source (virtually every cell can use it) while ketones serve as a backup energy source.

When oxaloacetate levels decrease in the liver (this is most effectively done by restricting carbs) and/or Acetyl-CoA levels increase (this occurs when more fatty acids enter your liver) enough so that acetyl-CoA starts to build up, the acetyl-CoA will then enter ketogenesis to produce ketones rather than entering the TCA cycle.

By restricting net carbs, you will directly decrease oxaloacetate levels in the liver and indirectly increase acetyl-CoA levels (by eating more fat). If that carb restriction is accompanied by a calorie deficit, then more fatty acids will be liberated from your fat cells which will also increase acetyl-CoA levels in the liver. Altogether, this stimulates ketogenesis.

Research indicates that the upper limit of carb intake needed to maintain ketosis seems to be 50 grams for most people. Restricting carbs more than this will help shift the oxaloacetate and acetyl-CoA levels in the liver to a greater extent, stimulating more ketone production. This strategy can also cause you to naturally eat fewer calories, which liberates more fatty acids from fat cells and increases acetyl-CoA levels even further.

I hope that clears up any confusion. If you have any other questions, please let me know.

Great question! There is no scientific source that explicitly identifies what carb limit is best for quick fat-adaptation. However, after digging through the literature and talking with many keto dieters who rigidly track their blood ketone levels, we’ve found that a good starting point for most people is staying below 35 grams of daily carb consumption.

The scientific mechanism behind this recommendation is the relationship between net carb intake and ketone production. When you consume more net carbs, your body will burn less fat and ketones for fuel.

Conversely, if you limit net carb intake, your body will need to burn more fat and ketones for fuel. Thus, by restricting net carb intake, you will burn more fat and ketones, which forces your body to become fat-adapted more quickly.

50 grams of carbs per day seems to be the cut-off point that causes most people to enter ketosis (and burn more fat), but eating fewer than 35 grams of carbs is a better option for producing ketones more quickly, burning more fat for fuel, and sustaining deeper levels of ketosis.

I’m glad you enjoyed the article! I couldn’t resist adding that little quip in there 🙂

Hilarious and informative article! Will definitely start following!

And for those who want to try keto for themselves, we are providing the information to help them so that they understand what’s behind it. Unfortunately, I cannot possibly personalize it to every reader specifically, so I focus on providing everyone with the concepts and strategies that will legitimately help. It is the reader’s responsibility to determine what they are capable of doing, and they are not required to follow all of our recommendations by any means.

Keto is most definitely not for everyone and is difficult to adjust to in our current food environment, but if people want to try it and see if it works for them, then they can find the info they need here.

Exercise is the same – it’s best if you can do it, but if not just take it at your own pace until you’re at a level you are comfortable with. Again, we’re just offering advice on the best way to get to your goals. Take it with a grain of sand and do it at your own pace if needed.

From what I’ve read and experienced, you’ll only stay in ketosis consistently if you are restricting carbs enough so that your liver produces ketones without the help of supplements. The MCTs will just be converted to ketones until there are no more left. Therefore, they probably won’t affect your carb limit at all.

The general rule that we recommend for entering ketosis is consuming no more than 35 grams of total carbs and 25 grams of net carbs.

Great question.

The general rule of thumb is to eat fewer than 50 grams of carbs, however, even this can be too high for some people. (This is partly why we recommend starting at 35 grams of total carbs per day.)

The absolute maximum depends on the person’s genetics, how keto adapted they are, how much they exercise, their lifestyle, etc.

It is possible, albeit much less likely, to stay in ketosis while eating 70 grams of carbs. To do this, you most likely have to be keto adapted and exercising regularly for around one hour a day. Pregnant women and women who are breastfeeding might be able to stay in ketosis by eating 70 grams of carbs per day as well.