If you’ve ever tried to lose weight, you’ve probably heard about the importance of a calorie deficit — but what does that mean?
Being in a calorie deficit means “you eat fewer calories than your body needs,” explains Dana Huns, PhD, MPH, RD, a senior dietitian at the Ronald Reagan UCLA Medical Center.
Depending on how many calories you remove from your diet, you can be in a slight calorie deficit or a significant calorie deficit, says Emily Tills, MS, RDN, CDN.
Of course, it’s not as easy in practice as it is in theory, as you already know if you’ve ever tried to reduce your calorie intake. And if you run a calorie deficit long enough, Tills adds, your body can metabolically adapt to conserve energy.
Here’s what you need to know about creating a calorie deficit and avoiding potential pitfalls.
How many calories do you need to eat per day?
Before you create a calorie deficit in your diet, you need to determine how many calories your body needs each day to maintain your current weight.
According to the Dietary Guidelines for Americans, the average person ages 21 to 50 needs 2,200 to 2,400 calories per day. The average sedentary woman in the same age range needs 1,800 to 2,000 calories per day.
However, the exact number of calories needed to lose or maintain weight is personal to you. This can be influenced by a number of factors, including muscle mass, fat mass, nutrition and dieting history, and overall health history, Tills says.
You don’t have to figure these things out alone. “There are predictive equations that can be used to estimate how many calories we need in a day,” Hunes explains.
A good example is the National Institutes of Health’s Body Weight Planner, which is based on your gender, height, current weight, and activity level. While this can be a useful tool, your best bet is to consult a registered dietitian who can give you their professional opinion and a personalized plan.
Once you have this number, determine how close or far you are from it by tracking what you eat and drink for a week. From there, you can calculate how many calories you need to cut from your normal eating plan each day to run a calorie deficit.
How do you run a calorie deficit?
According to Huhn, you can run a calorie deficit in three different ways: through diet alone, through exercise alone, or through a combination of the two. (If you’re relying on exercise for part of your calorie deficit, be aware that we often overestimate calories burned during exercise, and cardio machine calculators aren’t always accurate.)
“Start with a mild deficit of 200 to 300 calories to help shed fat and lose weight,” Tills advises. For example, if you’re currently eating 2,000 calories per day, start your calorie deficit by aiming for 1,700 to 1,800 calories instead.
If you’re on the heavier side, you may be able to start with a more significant calorie deficit, Hunes says.
However, before starting anything, consult a registered dietitian and your doctor – and make sure you’re not eating so little that it affects your health.
The next step is to decide how long you plan to run the calorie deficit. Tills suggests setting a time-based goal — for example, you might plan to run a calorie deficit for four months, followed by a one-month break at maintenance calories.
This can be more helpful than a weight-based goal (“I’ll run a calorie deficit until I get to my goal weight”) because a weight-based goal doesn’t take into account the muscle mass you’ve gained or hormonal fluctuations. Along the way.
Even during a calorie deficit, it’s normal for your weight loss to stop at a certain point. “Many people plateau at some point during their weight loss as their body adjusts to a new energy intake,” Hunes explains. If this happens, re-evaluate the baseline of how many calories you need per day. When you lose weight, your body needs fewer calories, so you may need to recalculate how many calories you need to lose weight.
7 Ways to Reduce Your Calorie Intake
When you’re starting out on a calorie deficit, you want to go for the low-hanging fruit. That means prioritizing the easiest ways to cut calories first. Here are seven simple tricks to help you stay in a calorie deficit.
- Remove excess sugar from your diet.
- Cut back on “liquid calories” from juice, soda, and alcohol.
- Measure the cooking oil. (They have about 120 calories per tablespoon!) Or use a cooking spray instead, like this avocado oil spray.
- Fry instead of bake, grill or fry foods.
- Use smaller portions of calorie-dense toppings like mayo, sour cream and guacamole, and be more mindful when eating these sauces.
- Swap dairy products for low-fat versions.
- Choose lean cuts of meat.