You’ve probably heard the common saying, “A calorie is a calorie,” which means that it doesn’t matter where your calories come from, because they all impact your weight the same.
However, we’re now also seeing more studies showing that not all calories are made equal, and the kind of food you eat indeed affects your weight differently. We’ll discuss more about calorie counting on keto below, starting with the definition of calories.
What Are Calories?
Calories are essentially the energy that comes from the food and beverages you consume. Your body needs calories to carry out tasks. This includes not just your daily physical activities, but also cellular activities like protein metabolism and the Krebs cycle (1).
Macronutrients (protein, fat, and carbohydrates) also provide different calories per gram. Protein provides 4 calories per gram, fat provides 9 calories per gram, and carbohydrates provide 4 calories per gram. Out of these three macros, it’s the carbs that make up most of people’s calorie intake worldwide — about 45–65% of their total calories (2).
Do Calories Matter on a Keto Diet?
Calories in, and calories out still matter regardless of the diet you’re on. Because, fundamentally, consuming more calories than you expend (via basic metabolism and physical activity) leads to unwanted weight gain.
But here’s what you need to know as well: This concept doesn’t paint the whole picture. As it turns out, other factors play a role in weight loss, as shown below, which explain why counting calories on keto isn’t everything.
One advantage of the keto diet is that it increases fullness and satiety, and causes you to feel less hungry (3)(4). This shows us why calories in vs calories out isn’t the whole story, since keto can naturally decrease your calorie intake anyway. A study published in Frontiers in Psychology explained that ketosis boosts satiety by releasing cholecystokinin (CKK), a gut hormone that regulates appetite (5).
The thermic effect of food or TEF
Eating can burn calories too, not just exercise. Yes, certain foods tend to make your body burn more calories than others. This concept is known as the thermic effect of food (TEF) or diet-induced thermogenesis (DIT). Protein, in particular, has a higher thermic effect than fat or carbohydrates. Check out the values below (6):
- Protein: Increases your metabolic rate by 15-30%
- Fat: Increases your metabolic rate by 0-3%
- Carbohydrates: Increase your metabolic rate by 5-10%
It’s because of this TEF concept that some people on keto opt to consume more protein not just to build muscle mass, but also to promote weight loss.
There’s truth in the saying that food quality and not calories is what really counts. Focusing more on real foods will set you up for long-term optimal weight control.
Here’s why: Unprocessed keto foods, such as meat, seafood, poultry, non-starchy fruits and vegetables, are packed with vitamins and minerals that properly nourish your body. (It’s commonly believed that cravings are your body’s way of telling you that you lack certain nutrients.)
Ultra-processed foods, on the other hand, contain empty calories — meaning, these calories are void of nutrients or have very little to no nutritional value. Furthermore, such options often contain added sugars and vegetable oils that cause inflammation.
How Many Calories Can I Have On Keto?
Since you already know that calories aren’t the only thing that matters, do you count calories on keto? Some people want to, while others don’t. But if you find it helpful, then your number of calories will depend on various factors, including your goal: lose, maintain, or gain weight.
How to Count Your Calories on Keto
Ready to know your calorie needs? Start by determining whether you want to lose weight, maintain it, or gain weight on keto. In addition, you’ll have to consider personal details like your age, gender, weight, height, and activity level.
There are various ways to know your calorie needs, and the most common and highly convenient solution is to use an online calorie calculator. You should be able to find lots of options online, enter your details, and get your numbers right away.
For a manual calculation, you can do it through any of these formulas:
If you consider yourself moderately active, just multiply your current body weight in pounds by 15. This will show you the calories you’ll need for weight maintenance. Note: “Moderately active” implies that you get at least 30 minutes of daily physical activity such as brisk walking, jogging, or active gardening (7).
Another way to determine your calorie needs on keto requires finding your basal metabolic rate (BMR), determining your activity level, then multiplying the answers for both to get your calorie needs. You can refer to the steps below:
Step 1: Find your BMR
- Women: 655 + (4.3 x weight in lb) + (4.7 x height in inches) – (4.7 x age in years)
- Men: 66 + (6.3 x body weight in lb) + (12.9 x height in inches) – (6.8 x age in years)
Step 2: Multiply your BMR by the appropriate activity factor (using the Harris-Benedict equation):
- Sedentary or little to no exercise: BMR * 1.2
- Light exercise (1-3 days a week): BMR * 1.375
- Moderate exercise (3-5 days a week): BMR * 1.55
- Very active (6-7 days a week): BMR * 1.725
- Very active in addition to having a physical job: BMR * 1.9
Now, you should be able to get a good estimate of your daily calories.
Can Too Many Calories Kick You Out of Ketosis?
Yes, it’s highly probable to get knocked out of ketosis by consuming more calories than you need, especially if these calories come from carbs. And as you know, carbs break down into sugar, causing your blood sugar levels to rise.
As a general rule for someone following the keto diet, make sure to watch your carb intake so that you don’t go over your daily limit. If it helps, you can also create a calorie deficit and maintain or enter ketosis by increasing your activity level, prioritizing whole foods, and avoiding sugar.
However, you should also keep in mind that eating too few calories on keto consistently can lead to nutrient deficiencies and various health issues. Your workouts and productivity may also suffer as a result of not having enough energy. Therefore, do proceed with caution to create a safe calorie deficit and work with a registered dietician or healthcare provider.
Not all calories are made equal, and choosing the right foods can make a huge difference in your journey towards a fitter, healthier self. This entails eating whole, nourishing meals within your carb allowance.
Some people, however, prefer to count calories even when on a highly satiating diet like keto because it helps them stay accountable. Conversely, if tracking calories causes unnecessary stress, then it’s best to stop and practice eating intuitively instead. At the end of the day, you should always do what works for you. Remember to also prioritize quality over quantity.
- Osilla E, Safadi A, Sharma S. Calories. 2021 September 15
- Slavin J, Carlson J. Carbohydrates. 2014 November 03
- Gibson A, Seimon R, Lee C et al. Do ketogenic diets really suppress appetite? A systematic review and meta-analysis. 2015 January
- Johnstone A, Horgan G, Murison S et al. Effects of a high-protein ketogenic diet on hunger, appetite, and weight loss in obese men feeding ad libitum. 2008 January
- Paoli A, Bosco G, Camporesi E et al. Ketosis, ketogenic diet and food intake control: a complex relationship. 2015 February 02
- Pesta D, Samuel V. A high-protein diet for reducing body fat: mechanisms and possible caveats. 2014 November 19
- Harvard Health Publishing. Calorie counting made easy. 2020 July 11