One of the most frequently asked questions I get about keto is: “Do I have to be in ketosis to burn body fat?”
The short answer: no.
This is a major myth that I think is somehow being spread now that the keto diet has gained traction and popularity. And, because keto is known for being a diet that can make losing body fat a lot easier for many people.
Keto Myth: If you want to burn fat, you need to be in ketosis
Truth: Being in ketosis is not the same as being able to burn fat. All being ketosis means is that there is a certain level of ketones in your bloodstream, which isn’t a requirement for burning fat for fuel.
In fact, being in ketosis is also not a guaranteed path to fat loss. You can easily be both in ketosis and either remaining your same bodyweight or gaining weight.
While having ketones present in your bloodstream and the ability to burn them for fuel has its own set of benefits, fat loss does not require a state of ketosis!
Some important benefits of being in ketosis are mental clarity, appetite suppression and the ability to go longer between meals, increased energy levels, improved mood, better sleep, and improved digestion for those struggling with gut imbalances due to a diet high in refined carbs.
Let me repeat part of that: mental clarity and appetite suppression are two of the main benefits of being in ketosis.
Fat loss on a keto diet still requires, as with any way of eating, that your body senses that it needs to burn more energy than is coming in via the food you eat.
This means, if your body needs more energy than is supplied by your food, it will look to tap into fat stores for fuel. Eating keto makes that process a lot easier (read: feel more comfortable) than if you're eating high-carb/low-fat.
Now, is this simple calories-in-calories-out equation? Not exactly.
I'm not saying that calories are all that matter here. It's important to note that what drives our appetite, what drives our stress hormones up (and our body fat storage up), and what makes us store body fat overall can be based in lifestyle factors.
Lifestyle factors that can lead to storing more body fat (and make it harder to burn body fat):
- poor quality or insufficient sleep
- stressful lifestyle (go-go-go, perfectionism, being hypercritical and unable to relax)
- poor quality relationships (negative interactions, tension, lack of unconditional love)
- a job you hate
- a negative mental outlook or poor attitude
- over exercising
- under exercising / not exercising at all
- alcohol consumption
- unidentified and unmanaged food allergies
- and more!
All of these negative lifestyle factors can squash your fat loss efforts in a variety of ways. Some of these increase appetite (lack of sleep and high stress levels, for example), and some can slow your metabolism (not exercising and drinking alcohol, for example).
The bottom line: it's possible to burn body fat a variety of ways, and the two primary approaches people take are to either reduce their fat intake or to reduce their carbohydrate intake.
Keto pushes the reduction of carbohydrate intake to the next level with an extreme reduction in carbohydrates to a very low – typically around 30-50 grams of total carbs per day – level.
If you don't need to be in ketosis to burn body fat, then why would someone choose a keto diet over another approach?
The following is an excerpt from my book, Keto Quick Start, on burning fat with ketosis or not:
Reducing your intake of carbs and replacing them with healthy fats gets your body to ramp up its fat-burning machinery and become efficient at burning not just dietary fat but also stored body fat. That means that in moments when, as a sugar-burner, you’d be feeling “hangry” or light-headed or dizzy and desperate to eat something, you can actually burn body fat and feel good at the same time.
…Insulin moves glucose out of the bloodstream and into storage as fat when blood sugar is high. Glucagon, on the other hand, acts when blood sugar is low: it releases fat from storage into the bloodstream so that it can be used as fuel.
So when does blood sugar drop so that glucagon can pull energy out of fat cells and into circulation?
It’s important to remember these glucagon triggers—these are the magic moments when our bodies tap into stored body fat for fuel!
Let me expand on each of the situations where glucagon kicks in and outweighs insulin in the bloodstream to help your body burn stored fat.
FASTING: You’re in a fasted state when you haven’t eaten food for around eight hours or more. When you wake up each morning, provided that you slept for around eight hours or it’s been at least that long since your last meal, you wake up fasted. The term breakfast refers to that: you’re “breaking” the “fast.”
Intermittent fasting is simply intentional fasting on a regular basis. There are several kinds of intermittent fasting—for example, fasting for twenty-four hours once or twice a week or limiting yourself to 500 calories for two consecutive days each week. But the most popular method of intermittent fasting is eating within an eight-hour window each day, meaning there are roughly sixteen consecutive hours when you simply don’t eat. This is easiest to achieve if you fast overnight— for instance, from around 6 to 8 p.m., when you finish dinner, to 10 a.m. to noon the following day. So this is as simple as having your last meal or snack at 6 p.m. then eating again at 10 a.m. the next day, or having your last meal or snack at 8 p.m., then eating again at noon the next day.
HUNGER: Short of fasting, we also get a boost of glucagon into our bloodstream when we feel hungry, which clearly happens well before we’re in a fully fasted state. When you’re fat-adapted, that boost of glucagon lets your body tap into stored body fat, and that timespan between when hunger initially kicks in and when you eventually eat is pure fat-burning! And while you’ll feel hungry during that time, the fat-burning means your body is getting fuel, so hunger doesn’t become “hanger” and you can easily power through.
EXERCISE: When we exercise, we release endorphins that trigger an increase in glucagon. Exercise, especially weight training, is one of the most effective ways you can increase your body’s ability to burn stored body fat. Not only will you burn fat during the activity itself, but you’ll increase your muscle mass and resting metabolic rate (how many calories your body burns at rest) by increasing your insulin sensitivity. So get into the gym and lift those weights!
Low-Fat vs. Low-Carb: Which Wins for Fat Loss?
You actually can lose body fat through either a low-fat or a low-carb diet (among many other ways that are debatable in terms of their healthfulness).
The reason it’s possible to lose weight on a low-fat, high-carb diet lies in overall energy input versus output.
No, I’m not saying that fat loss is as simple as calories in versus calories out, but calories do matter! And so does physical activity, genetics, muscle mass, and overall health.
Even when we eat a high amount of carbs, we do occasionally burn fat, usually to fuel low- or moderate-intensity aerobic activity. In fact, our bodies rely on fat for most activities that we do day in and day out, with the exception of high-intensity exercise, which is fueled by glycogen (stored glucose). But daily activities will almost never burn more energy than we take in through food—so any body fat we burn is replenished by what we eat.
The beauty of being fat-adapted is that your overall appetite drops, so you’re not consuming more calories to replace those you burn.
It’s also easier to lose body fat when you’re eating fewer carbs because your body is trained to consistently pull energy from stored fat rather than constantly battling high blood sugar with more insulin to bring it back to baseline.
When comparing a low-fat diet to a low-carb one, the question to answer is: Does eating low-fat work for you? Meaning, can you maintain it long enough to lose an appreciable amount of body fat? Is eating that way enjoyable? How do you feel eating that way? And which way of eating feels more sustainable 80 to 95 percent of the time while allowing for an occasional off day when you eat more of the nutrient you’re generally avoiding (whether carbs or fat)?
For most people, a low-carb ketogenic diet beats a low-fat diet on all counts.
Eating to a ketogenic level of around 30 grams net carbs per day provides high satiety, a high level of enjoyment, and relative ease of compliance. In other words, you don’t feel like you’re starving all the time, as you’d often feel on a low-fat diet where you need to eat every two to three hours.
You can enjoy tasty foods like bacon, steak, butter, and avocados on keto, and it’s not that difficult to eat at home or eat out at a restaurant and order “around the bread,” so to speak.
Calories Do Count, Even on Keto
Whether you choose to eat keto or not, the reality is that overeating causes an energy (calorie) surplus, and that will lead to weight gain. Put simply, you can’t just eat keto foods or zero carbs while overeating fat and protein and expect to lose body fat. While keto is an extremely effective way to lose weight and body fat, calories still count!
I’m not going to suggest you micromanage your calorie intake, although the customization plans in [the book] and the SAVVY Keto Daily Trackers do break down calorie and macronutrient targets. These are targets, and aiming for the recommended grams of each macronutrient will get you there (or close enough).
You don’t need to count every calorie, but be aware of how much you’re eating and whether you’re eating because you’re truly hungry or because you’re trying to satisfy an emotional craving.
Recognizing your own patterns will be a pivotal part of your success. Tune in to your appetite, notice how it drops over time as your body adapts to burning fat for fuel, and then, if losing body fat is your goal, keep your portions in check.
End of excerpt.
Hungry for more? Grab a copy of my new book, Keto Quick Start for all this and more, including 4 weeks of meal plans and over 100 easy recipes!
In the book, I take you through your first 4 weeks of starting keto eating real, whole foods, then carry you forward with how to customize it from there. You’ll then learn how to add carbs (or not) depending on your lifestyle and activity level, and how to build your own keto plate according to specific macros of protein, fat, and carbs to reach your goals. I’m even giving you an easy-to-use template for making sure you’re eating plenty of everything you need and avoiding the carbs you’re trying to avoid so that YOU can efficiently burn fat AND become fat-adapted.