One of the main questions I had regarding nutritional ketosis is regarding the potential for weight gain despite rigid adherence to the high fat, low carb, and moderate protein model recommended by Volek and Phinney. In my reading of both of their books, they write frequently of how nutritional ketosis promotes fat burning and subsequently weight loss and body recomposition, and the benefits of ketoadaptation for athletes.
But they never really satisfactorily answer the question of whether or not you can actually gain weight from nutritional ketosis and exactly how important overall caloric intake is in weight loss vs weight gain. I tried to do some research online but I didn’t really find much information out there, so I figured I’d try to ask some people that are well respected in the field.
I posed this question to Robb Wolf on his website and this was his response:
“I think we will see some studies looking at exactly that out of NUSI.”
When I asked Jimmy Moore, this was his response:
“The calorie people say over consuming them will lead to weight gain. But none of those studies examined someone with adequate levels of blood ketones (not measured) and how it impacts their weight.”
And this was the Caveman Doctor, Colin Champ’s (wonderful podcast btw) thoughtful response to my question:
“Based on the calorie in/out, etc. you will. I personally have tried to gain weight on it and have been unable to. Perhaps I am not eating enough calories or something else is going on (whether digestion, hormonal, or unable to reach that caloric threshold). That being said, I have self experimented with extremely high caloric intake. I think it is likely individualized because I have definitely put weight on with lower calories on a higher carb diet. Clearly this is the threshold for my “carbohydrate intolerance”. which nearly everyone has. We need more studies evaluating this.”
Jimmy Moore actually recently wrote an article on CarbSmart where he concludes from his own n=1 experiment that:
“But the more likely explanation is the ketones produced by a well-formulated high-fat, moderate protein, low carb diet are at a sufficiently high level that calories are automatically kept in check without really worrying about them because both my insulin and leptin levels have normalized.”
According to the responses above, it doesn’t seem like there is very good data out there except for anecdotal reports.
In my own experience after 30 days (I’m working on an official writeup of this) of mostly being in nutritional ketosis and having my weight being back at square one at 180 lbs I have to say that my conclusion is mixed. I noticed more positive changes after the folks at the LowCarbFriends forum urged me to keep a food log to have a better picture of my macronutrient and overall caloric intake, and it wasn’t until I implemented this that I discovered that despite being in nutritional ketosis and eating until satiety, my overall caloric intake was way higher than expected. I hadn’t lost any weight by this point and attribute this to my increased caloric intake.
I’ve been fiddling with my macro intake in the past few days and have only recently discovered that I experienced increased satiety without bad hunger pangs once I changed my lunch to include more meat (higher protein to fat ratio) from hard cheeses (lower protein to fat ratio).
My conclusion, which I think agrees with Jimmy’s, at this point in my n=1 experiment is:
Caloric intake IS the most important factor if the primary goal is weight-loss (fat-loss). The benefit of nutritional ketosis is that it promotes the conditions under which your body self regulates its overall caloric intake by increasing satiety and appetite suppression (if using the correct source of foods) once adapted to ketones as the primary source of fuel in which supplies are plentiful. Your body is no longer subjected to the extreme highs and lows in blood sugar and the accompanying hormonal responses when using carbohydrates as the primary source of fuel which often lead to an increased appetite.
I got a great response from one of the forums regarding this post, drjlocarb from the Low Carb Friends wrote:
Calories do matter, but, the composition of those calories matter more.
1300 calories of high carbs, low fat and protein = HUNGRY and weight gain
1300 calories of high protein, lower fat and low carb = gluconeogenesis and high fasting glucose
1300 calories of high fat, low carb and mod. protein = decreased hunger, lower fbg [fasting blood glucose], higher blood ketones
And another idea that first drew me to nutritional ketosis which I neglected to mention was that nutritional ketosis promotes burning of your body’s fat stores for energy, so the entire time you’re in NK, you’re constantly burning up your fat stores, as opposed to available carbs/glycogen… at least in theory.