We are going to talk today about how many calories a day might you need in order to lose weight. Many people would be concerned about their body weight and resort to fitness programs. But in order to achieve that dream figure, one needs to know what is the appropriate daily calorie consumption for their body weight.
This Is Exactly How Many Calories You Need To Lose Weight
Calories are those little units of energy we consume whenever we eat, well, anything. And they are arguably the most talked-about part of any weight-loss journey.
The general rule is that if you eat more calories than you use, you’ll gain weight. And if you take in fewer calories than you use, you’ll lose weight. And if those numbers are more or less even, your weight will stay about the same. It seems simple, but the number of calories you need to lose weight, maintain weight, or gain weight from lean muscle depends on your activity levels, body size, hormones, sleep, and more, explains registered dietitian Wesley Delbridge, R.D., a spokesman for the Academy of Nutrition & Dietetics. So figuring out how many calories you need per day can be crazy-complicated.
And, it’s also important to remember that, when it comes to cutting calories for weight loss, lower is not always better. According to the American College of Sports Medicine, your calories should never dip below 1,200. That’s because most women, unless they are very small, will burn more calories than that doing literally nothing, says registered dietitian nutritionist Jonathan Valdez, R.D.N, C.D.N, owner of Genki Nutrition and a spokesperson for the New York State Academy of Nutrition and Dietetics. “Less than that and you could shock your body into starvation mode, which will slow your metabolism, decrease your muscle mass, and likely keep you from getting the nutrients you need to sustain daily activity,” Delbridge explains.
So, if you’re asking yourself, “How many calories do I need a day?” read on as experts explain what you need to know to get your calorie intake just right.
How To Determine Your Base Calorie Needs
In order to figure out how many calories you need to lose, or even gain weight, you first need to determine how many you need to maintain. As a first step, Delbridge recommends checking out the latest Dietary Guidelines for Americans, as they can give you a good estimate for what you need to stay the same weight. The guidelines say young women should aim for 1,800 to 2,400 daily calories, depending on age and activity level, but that range isn’t necessarily tailored to your specific needs—so it’s not as precise as it could be.
For a more exact number, start by finding your basal metabolic rate (BMR), which is the minimum number of calories your body burns at rest, suggests physical therapist Grayson Wickham, D.P.T., C.S.C.S., founder of Movement Vault. Your BMR accounts for 60 to 75 percent of your total daily calorie burn, according to a review in Medicine and Science in Sports and Exercise.
“To most accurately calculate your BMR, you’d need to go to a lab to have your carbon dioxide and oxygen analyzed after having fasted for 12 hours and slept for eight. But, that can be a little pricey and a rough estimation of your BMR can be found using a few different equations,”says Wickham.
One study published by the Journal of the Academy of Nutrition and Dietetics found the Mifflin-St. Jeor equation to be highly accurate, so it is now considered the gold standard when it comes to calculating BMR. For comparison’s sake, however, some experts prefer the Harris Benedict equation for determining BMR.
For women, the Mifflin-St. Jeor equation equation is: BMR = (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) – 161.
So, for a 25-year-old woman who is 5’4″ and weighs 150 pounds, the BMR equation would look like this: BMR= (10 x 68) + (6.25 x163) – (5 x 25) -161 = 1,413 calories
For women, the Harris Benedict equation is: BMR = 655.1 + (9.563 x weight in kg ) + (1.850 x height in cm) – ( 4.676 x age in years).
So, for the same woman, the BMR equation would look like this:
BMR= 655.1 + (9.563 x 68) + (1.850 x 163) – ( 4.676 x 25) = 1,490
As you can see, the results for both are slightly different, but they’re pretty darn close, says Wickham. When you find your BMR on your own, consider it a really good estimate, not a hard-and-fast rule, he adds.
For both equations, finding your BMR requires your weight, height, age, and gender (yes, guys have their own equation). Wondering why? “The more you weigh and the more mass you have, the more fuel you need to sustain your organs,” explains Valdez. That’s why people who weigh more have heavier BMRs.
Age is a factor in the equations because, as you get older, muscle mass declines by 5 or so percent each decade after the age of 30, Wickham explains. This might change as more women start strength training, but as a general rule, that’s fair, he says. And if you’re wondering why the formula is different for men and women, it’s because research published in The Journal of Clinical Investigation shows that a woman’s BMR is typically around 5 to 10 percent lower than a man’s.
Now what? Once you know your BMR, you know the bare minimum number of calories you would need to keep your body alive if you were going to lay in bed all day, says Wickham. But you need to take into account everything else you do that burns calories (walking the dog, folding laundry, climbing five floors of stairs to your apartment, bi-weekly CrossFit class, Thursday evening yoga…).
To do that, multiply your BMR by the factor that best represents your activity level.
- If you are sedentary = BMR x 1.2
- If you do light exercise 1-3 days a week = BMR x 1.375
- If you exercise at a moderate intensity 3-5 days a week= BMR x 1.55
- If you are exercise at a high intensity 6-7 days a week = BMR x 1.725
- If you are into two-a-days or have a physically demanding job = BMR x 1.9
Using Calories Calculations to Manage Your Weight
- Keep track of how many calories you currently eat each day. When you first start your attempt to lose weight, it may be helpful to keep track of how many calories you’re currently eating.
- Keep a food journal or use an online calculator to help you get an estimate of how much you currently consume.
- Compare this amount to your calculated and activity-adjusted BMR. If the numbers aren’t even remotely close, it may be easier to start your diet by consuming your calculated amount of calories daily.
- Consuming a significant amount of calories less than you’re typical day might be difficult. Decrease slowly by first adjusting your diet to line up with your activity-adjusted BMR level.
- Don’t eat less than your calculated BMR. It’s a bad idea to consistently make your daily caloric intake lower than your BMR. When your body doesn’t take in enough calories each day to sustain basic functions, it starts burning muscle for energy. This will make maintaining your weight loss more difficult in the long run.
- Very low calorie diets aren’t typically considered safe or appropriate for weight loss. They do not provide enough flexibility for you consume an adequate amount of protein, vitamins or minerals that are essential to your health.
- Try to keep consume at least 1,200 calories daily. This is generally recommended to by the absolute lowest amount of calories to take in daily.
- Keep a food journal. Consider keeping a food journal that lists everything you eat, as well as the calories per serving and how many servings you had. Studies show that those who journal their foods regularly stick to their diet plans longer and lose more weight.
- Search online for free apps or websites that allow you to enter what you ate — some will even calculate the calories for you. Try MyFitnessPal or Super Tracker by the USDA. You can also log your activity level and the amount of exercise you get each day.
- Seeing the actual amount of calories you consume each day will force you to take responsibility for your health and cut back on eating. Be vigilant about logging everything that goes into your mouth, and you’ll find it’s easier to stick to your diet.
- Weigh yourself regularly. Another important component of weight loss is tracking your weight and overall progress.
- Studies have shown that those dieters who weighed themselves regularly were more successful long-term than those who didn’t keep track on their weight.
- Weigh yourself about one to two times per week. Try to get on the scale at the same time of day (try for first thing in the morning after you’ve just emptied your bladder) while you’re wearing the same clothes for the most accurate record of progress.
- If you’re not losing weight, reevaluate your total calorie intake. You may need to cut out more calories or be more accurate with your food journaling.
Should I count calories?
The short answer is no. Once you calculate how many calories you need to maintain your current weight, what do you do with that information? Well, nutritionists say, not much.
“I personally don’t use calorie calculators or recommend them,” says Ariane Hundt, a clinical nutrition coach and fitness expert in New York City.
“The reason is that they tell you how many calories you burn at rest. But this is an artificial number because there are so many variables that affect it—activity level, health status, stress levels, hormone changes, and more. Even if you knew that number, it wouldn’t translate well into reality because we don’t live in a bubble or lab environment. Our metabolism isn’t a constant but affected by many things daily, especially for women whose hormonal changes affect one’s nutrition and exercise needs.”
The number really only gives you a broad picture of whether your usual calorie intake jibes with the estimate.
“Calorie counting can be beneficial for people who are trying to understand how much food they’re actually eating, portion sizes, and reconnecting with their hunger cues,” says Alicia Gould, MS, RD, CDN. “On the other hand, counting calories can become problematic. It can lead to an unhealthy and obsessive relationship with food.”
But what about weight loss?
The standard school of thought suggests that to lose weight, a person needs to eat fewer calories than they burn. But it doesn’t always work that way. Calorie counting can be tedious and stressful, and researchers are finding that it’s not usually worth it.
In a large clinical trial published in JAMA, dieters were able to lose large amounts of weight by eating plenty of fruits, vegetables, and other hunger-satisfying whole foods. They also ate less sugar and refined grains. They weren’t required to cut or even count calories. And they were able to eat as much as they wanted to avoid feeling hungry.
“Calories aren’t nearly as important as where they come from,” Hundt explains. “For example, if you needed 1,500 calories a day to lose weight, and you spend them on cakes and cookies, you will still get fat because of the fat storage effect sugar has. If you spent them on protein and veggies, you’d lose weight because of the blood-sugar-balancing, fat-burning effect, and appetite satiation this combo has.”
Truthfully, cutting too many calories can wreak havoc on your body. “Eating too little will backfire,” Hundt says. “It can slow down the thyroid function in a matter of days, make someone extra-hungry, create cravings and willpower issues hard to battle, and can slow the metabolism so much over time that a ‘yo-yo’ effect is inevitable. Also, muscle loss is a risk of a low-calorie diet, along with hormonal imbalances that are hard to resolve when practiced for a long time.”
HIIT workouts can also help if you’re looking to maximize calorie burning. Check out our HIIT workouts in the Aaptiv app.
What should I do instead?
There isn’t one eating plan for weight loss that works for everyone. Don’t worry so much about how many calories a BMR calculator tells you to cut. Instead, consider some other courses of action to improve your diet, including:
Stick to whole foods as much as possible.
Processed foods have added sugar and empty calories that can easily get in the way of nutrition goals. Stick to lean protein, fruits, veggies, and complex carbs as much as possible.
Keep a food diary.
“It helps you understand your hunger cues, which is especially helpful if you find yourself grazing the kitchen or the office pantry during the day,” Gould says. “It also helps you recognize whether you’re actually hungry or just bored, which can help identify and address issues of emotional eating. If you start noticing a pattern, you can then seek an alternative to manage this behavior.”
Balance your meals.
“Remember that there are certain foods that keep you fuller and satisfied longer; this will inherently eliminate the mindless eating we’ve all been so accustomed to,” Gould says. “Protein, whole grains, fiber, and fat together is the ultimate combination of balanced nutrition.”
Counting macronutrients allows you to adjust your diet to the proper proportions that will help you achieve your desired results.
Adjust your diet.
On days you work out, you’re going to be hungrier because of all the calories burned. Eat extra veggies and protein to keep your metabolism going. On rest days, consider eating fewer carbs.
“Mindful eating and the benefits of whole foods are definitely hot topics in the field of nutrition and ones that I fully support,” Gould says. “This approach to eating and thinking is more of a lifestyle rather than a rigid diet and allows for more food freedom instead of terming foods ‘good’ or ‘bad.’ Maintaining a diet that is high in fruits and vegetables, lean protein, healthy fats, and occasionally some chocolate (We’re human, right?) is way more beneficial than counting calories.”
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