# How many calories you should eat a day whether you're trying to maintain, lose, or gain weight

Erin Heger,Samantha Cassetty
• How many calories you eat a day depends on your physical activity level, age, and sex.

• If you want to lose weight you need to eat fewer calories than your body burns.

• If you want to gain weight, you need to eat more calories than your body burns.

• Visit Insider's Health Reference library for more advice.

The number of calories you should eat each day depends on several factors, including your age, weight, sex, and activity level.

It also depends on your goals: Are you looking to lose weight, gain weight, or maintain weight?

Here's what you need to know about calorie recommendations and how to determine your own.

## How many calories you should eat a day

The following chart breaks down estimated daily calorie needs for maintaining weight based on your age, sex, and activity level.

How many calories you need to eat depends on two main factors:

1. Physical activity

2. Basal metabolic rate

Your level of physical activity is generally defined in three different categories:

• Sedentary - daily activities but no concentrated exercise

• Moderately active - light physical activity, like walking, for about 30 to 45 minutes a day for three to four days a week

• Active - working out most days of the week for about an hour

When determining how many calories you need, it's also important to consider basal metabolic rate (BMR), which accounts for 60% of the calories you burn. BMR is the calories you need to perform basic functions, like breathing or pumping blood, says Natalie Allen, RD, clinical assistant professor of biomedical sciences at Missouri State University.

There are several equations used to calculate BMR, including the Mifflin-St. Jeor equation:

• Men: (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) + 5

• Women: (10 x weight in kg) + (6.25 x height in cm) - (5 x age in years) - 161

Important: If you consume fewer calories than your BMR, you may slow down your metabolism, putting you at risk of starvation mode. This is when your body conserves energy and fat, making it difficult to lose weight.

## How many calories should you eat a day to lose weight?

To lose weight, you will need to be in a caloric deficit. This means you need to eat less calories than what's required to maintain your weight.

Allen says the most effective ways to create a deficit are:

• Increasing physical activity. The Centers for Disease Control (CDC) recommends moderate physical activity for at least 150 minutes a week, but you may need more exercise than this to create a deficit, depending on how many calories you are consuming.

• Decreasing food intake. Consult your doctor or a registered dietitian to develop a plan for decreasing calorie intake to lose weight.

Here is a breakdown of the calorie deficit needed per day to lose weight. It's important to note that these are general rules of thumbs and that how many calories it will take to lose a pound can vary depending on the person.

 Weight loss per week Calorie deficit needed per day (on average) 0.5 pounds 250 1 pound 500 2 pounds 1,000

Important: Your weight loss goals and diet should be discussed with a doctor or a registered dietitian, Allen says. In general, aiming to lose about 0.5 to 1 pounds a week is considered healthy for most people.

The greater the deficit, the more rapid the weight loss, but in general, you should not restrict your calories to fewer than 1,200 a day because it's more difficult to meet vitamin and mineral requirements, Allen says. It can also slow down your metabolism and may result in gaining that lost weight back.

Eating too few calories can lead to issues, such as:

## How many calories should you eat a day to gain weight?

To gain weight, you'll need to be in a calorie surplus, meaning you eat more calories than you burn. How many calories you need to add depends on how much weight you're looking to gain.

Generally speaking, adding about 500 calories a day will amount to a pound of weight a week, but adding calories alone isn't enough to build muscle.

"When bulking up, your body requires a proper stimulus first before it can build muscle, like resistance training," says Dimitar Marinov, MD, an assistant professor at the Medical University of Varna, Bulgaria. "A 10-20% [calorie] surplus is usually a great start but some people have a more adaptive metabolism and might require an even higher surplus to gain weight."

When gaining weight, it's important to make sure you're eating an adequate amount of protein and continuing to exercise, so you gain muscle and not just fat, Allen says.

While body fat is essential, the higher percentage of fat you have the greater your risk of certain health conditions like high blood pressure, heart disease, and diabetes.

"To build or preserve muscle, it is important to consume protein regularly, at each meal, throughout the day," Allen says. "A general goal for most people looking to gain weight is 30 grams of protein at each meal."

General advice: Eating nutritious foods is important whether you're looking to gain, lose, or maintain your weight, Allen says. If you are wanting to increase your calories and gain weight, make sure you are doing so by eating a well-rounded diet of fruits, vegetables, lean protein, and whole grains.

## Insider's takeaway

How many calories you need to eat a day depends on many factors, including your age, activity level, and whether you want to lose, gain, or maintain your weight. For guidance on determining your caloric intake, reach out to your doctor or a registered dietitian.

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