How Ketosis Helps You Lose Weight Through Suppressed Appetite
By: Dave Asprey
One of the reasons The Bulletproof Diet with Bulletproof Coffee works so well for people looking to lose weight is that Bulletproof Intermittent Fasting helps your body to more easily enter a state called cyclical ketosis, which is great for a whole bunch of reasons.
Ketosis is a cornerstone of becoming Bulletproof; listen to these recent Bulletproof Radio episodes with ketosis experts Jimmy Moore and Dominic D’Agostino to get the scoop on how and why it works. It’s what happens when your body switches to burning fat instead of sugar for energy, and it only happens when you eat almost no carbohydrates, or when you hack it using certain kinds of oils.
Many people first stumble upon the idea of ketosis while looking for a weight loss strategy. That can be a major part of it for so many people out there who have tried just about every other diet out there but haven’t seen the results they’d hoped for. But when people experience the mental clarity and focus that ketosis brings, the game changes!
This post walks you through one of the most important yet underrated mechanisms that makes ketosis so effective for people who have tried everything else to lose weight and failed to keep it off: appetite suppression.
Ketosis works for weight loss in the short term, but that’s not why it’s so amazing. Short term weight loss is easy (I’ve lost at least 200 pounds of short term weight…because it always roared back on with a vengeance so I could lose it again!) When you look at keeping your weight off forever, ketosis provides a level of appetite suppression that is actually liberating. Ketosis helps you literally stop thinking about food all the time.
Why Calorie Counting Is So Ineffective
One of the reasons old-fashioned, calorie-restricted diets tend to fail is because these diets make you really hungry and cause food cravings.
Cutting calories to lose excess weight changes your hormones that control hunger and satiety so that after you starve yourself enough to lose some weight, your brain and gut start making your hormones work against you.,
Your hormones scream, “eat more and gain that weight back!” So you do. And so begins a lifetime of yo-yo dieting, the one I used to live.
But it doesn’t have to go that way for you.
As tons of Bulletproof success stories have shown, it’s actually easy to lose weight, regain normal hormone levels and control your appetite through Bulletproof Dieting. If you eat the higher amount of healthy fats recommended on the Bulletproof Diet, get your carbs mostly from nutrient-rich vegetables, and use Bulletproof Intermittent Fasting, then you’ll be doing your hunger-and-weight-control system a favor by dipping often into the fat-burning state of ketosis.
Studies consistently show that when you combine ketosis with a low-calorie diet, you will likely experience an increase in appetite in the first days of your diet, and then a decrease in appetite and a return to normal appetite control in just a few days but you have to achieve ketosis for it to work.
Or, you can skip the whole calorie-restriction, hungry-all-the-time thing, and just use ketosis to its full advantage without making yourself hungry.
The Science Behind Using Ketosis to Suppress Appetite
Ketosis suppresses appetite in more than one way.
When you start eating more fat and cut out all those senseless carbs (sugar, bread, and the like), you tend to stop experiencing the blood sugar swings that plague most people on the Standard American Diet. These fluctuations cause intense hunger that keeps you lurching from one carb-heavy meal to the next, never feeling satisfied—and never reaching the deep fat-burning state of ketosis. But that’s not big news to most of us.
What’s exciting is that ketones suppress appetite in a variety of more subtle and significant ways because ketones can control hunger and satiety hormones. Scientists have identified that ketones impact cholecystokinin (CCK), a hormone which makes you feel full, and ghrelin, the “hunger hormone.”
Ketones and CCK
Your intestines release CCK after you eat, and it is a powerful regulator of food intake—so much so that injecting people with CCK (in a controlled study!) will cause them to cut their meals short.]
Your body secretes less CCK after you lose weight. In other words, when you are thinner, you will feel less sated with the same meal than you did before losing the weight. So you’ll crave more unhealthy foods. However, weight loss with ketosis keeps you from getting caught in this trap.
In fact, a recent study in the American Journal of Clinical Nutrition showed that even after 8 weeks of weight loss that resulted in significant reductions in CCK, just one week of ketosis returned CCK to baseline (pre-weight loss) levels. In other words, even if you use famine-level calorie restriction to lose weight, you’d better pound the butter and cut carbs at the end unless you want to crave food all the time.
Ketosis and Ghrelin
Ghrelin is called “the hunger hormone” because it increases appetite. It’s released from your stomach and intestines, with blood levels reaching their highest point during normal fasting. When you eat a meal, ghrelin drops in response to nutrients circulating in your blood.
When scientists give ghrelin to rats, they eat more, gain weight, and use less fat for energy. When us humans get ghrelin injections, it causes a 28% increase in food intake. When you lose weight you can bet your ghrelin levels go up – but not if you’re also in ketosis.
Ketosis completely suppresses the increase in ghrelin levels that occurs with weight loss. In fact, if study subjects had ketone levels higher than 0.3 mM during dieting, their ghrelin levels actually went down compared to baseline (pre-weight loss) levels. That means they wanted to eat less after they stopped dieting, instead of more!
Another study in the European Journal of Clinical Nutrition in 2013 reported that the hunger levels of weight loss subjects whose blood ketone levels were 0.48 mM were completely unchanged from baseline after 8 weeks of dieting, despite an average 12.5% decrease in body weight and a 13.4% loss of fat mass.
After two weeks of return to non-ketotic levels (blood ketones measured 0.19 mM), subjects’ rates of hunger and desire to eat were significantly higher than pre-weight loss levels. That’s why the Bulletproof Diet recommends cyclical ketosis, because if you’re in it a lot of the time, but not all the time, you never have to deal with that pesky gnawing hunger.
Because increased appetite following weight loss is one of the key factors in weight regain, this is nothing short of amazing.
You can be sure that ketones are the cause, because when scientists injected people with ketones (again, in controlled studies!) it has the same appetite-suppressing effects as diets that induce ketosis.
How Much Ketosis Is Enough Ketosis?
So what level of ketosis does the trick? A recent study published in January 2015 in Obesity Reviews found that a blood ketone level of 0.5 mM was sufficient to significantly suppress appetite in participants on a variety of diets. Typically, circulating levels of ketones are at ~0.1 mM in the average person after an overnight fast.
Depending on your metabolism, just one large cup of Bulletproof Coffee in the morning (without other foods) can raise blood ketone levels to levels that suppress appetite. At my buddy Zak’s house last year, I ate a lot of sushi with rice for dinner which ended my ketosis because I woke up with blood ketone levels of 0.1 mM, far below the appetite suppression levels in these studies. Then Zak handed me a large fresh-made Bulletproof Coffee. A half hour later, my blood ketone meter read 0.7 mM – more than enough to kick ass all day.
So there you have it – there are great reasons to be in ketosis at least some of the time every week, even if it’s the kind of mild ketosis you can bring on by hacking your morning coffee. The Bulletproof Diet book is full of ways to put this knowledge to use to end hunger and boost your energy – check it out if you haven’t read it!