Today I’d like to talk about Sam Feltham’s and more recently Jason Wittrock’s experiments, during which they ate more than 4000 calories/day on a Ketogenic Diet without gaining weight and why most of you would have very different results if you were to try the same experiment.
A Ketogenic Diet is a diet that is very low in carbohydrates, moderate in protein and high in high-quality fats. Calorie-wise, a ratio of approx. 5% carbs, staying under 20-25g of net carbs per day, 15-20% protein and 70-80% fat works well for a lot of people that are aiming to start Keto, get into Ketosis and to start burning body-fat more efficiently.
The goal for most of us is burning primarily fat for energy instead of sugar. When you’re running on glucose, you feel exhausted, tired and hungry when your sugar supplies are about to run out so you need to eat again. When you’re running on fat however, you’re able to use both the fat you eat as well as your body’s stored fat as a more efficient and long-lasting fuel. Even someone with a low body-fat percentage has tens of thousands of calories stored as fat that can be used for energy when no food is available.
Sam Feltham documented his 3 week experiment of eating more than 5000 calories/day of a low-carb Ketogenic Diet back in 2013 and didn’t gain any fat. And now Jason Witthrock, a bodybuilder that has also been spreading the Keto message for a while, just finished a new experiment, in which he was force-feeding himself 4000 calories of Keto food/day for 21 days. He also did not gain weight and had an even lower body-fat percentage at the end of the experiment than when he started. How is this possible and why would someone else gain weight trying the exact same thing?
Hormones are the most important factor when it comes to fat-loss, not calories. When you’re eating fat, insulin does not go up, unlike when you’re eating carbohydrates or protein. The fat gets stored in fat cells and when your body notices your fat mass going up, the hormone leptin goes up as well. Leptin is the satiety hormone that signals your brain when you’re full and that you have no need for more stored fat, so it makes you stop eating. It plays an important role in regulating how much you eat but also in how much energy you burn.
A fit, lean person is sensitive to leptin, which means he or she will feel full and stop eating when their leptin rises, so that the body weight can go down again. When that person is force-feeding himself past hunger like Jason Witthrock and Sam Feltham did, their metabolism speeds up in order to burn the extra calories they ate. Remember, this is only possible because insulin remains low on a Ketogenic Diet due to the low amounts of carbohydrates. Both of them would have easily gained fat eating that many calories on a high-carb diet. Actually, Sam even did two more experiments – in one he ate 5000 calories of a Vegan diet and in another one he ate 5000 calories a day on a high carb diet. He gained quite a bit of weight on both.
Now, if you are overweight, chances are you are resistant to leptin as well as insulin. This means that when eating fat, the fat goes into your fat stores. Normally, your body would respond by raising leptin, which it does. But, since you’re leptin resistant, meaning that leptin is unable to communicate with your brain properly, your appetite doesn’t go down as much and your metabolism doesn’t get increased the same way to burn excess fat that you ate.
And here is usually were a lot of people that are following a Ketogenic Diet and are aiming to lose fat make a mistake. They drink excessive amounts of bulletproof coffee, eat fat bombs or add tons of fat to every meal even though they’re not really hungry to begin with. By doing this, you’re burning primarily the dietary fat you’re taking in or maybe even storing some of it, instead of burning what’s already on your body.
Those 70-80% of calories per day you get from fat don’t need to come from the food you’re eating every day. If you’re trying to lose fat, reduce the amount of fat you eat, meaning you only add what is needed for you to be full and you don’t eat until you get hungry again. If you allow your body to get more calories from the fat it already has stored, you will lose weight more effectively.
Regular fasting, for example intermittent fasting for 16 hours or longer fasting intervals are a great way to burn off body-fat more quickly.
All of this does not mean that you need to be afraid of eating fat now.
A LCHF diet is still your best bet if you want to lose weight long-term. Just make sure you eat just when you’re hungry, just enough to be full and then stop. And consider incorporating regular fasting intervals to help you reach your goal more quickly.