What Is a Low-Calorie Diet?

In This Article

Following a low-calorie diet typically means consuming 1000 to 1500 calories per day. This creates a calorie deficit that can lead to weight loss. It can be effective, but it requires a lot of discipline in order for it to work and be safe. Ideally, you should seek help from a nutritionist or doctor so that you don't restrict your calories too much or miss out on essential nutrients.

What Experts Say

"A low-calorie diet is typically between 1000 to 1500 calories and used to promote weight loss. It should be followed with guidance from a professional to ensure all nutritional needs are met. Experts emphasize it is not appropriate for everyone, especially athletes and breastfeeding women."
Chrissy Carroll, RD, MPH

Background

Scientists have been studying low-calorie diets since as far back as the 1980s, investigating claims that they may slow the aging process. For weight loss, the science is simple: Take in fewer calories than you burn (via daily living and deliberate exercise), and you will lose weight.

However, just because the science is simple does not mean actually following the diet is simple. It takes planning and effort to overcome hunger cues and to make sure those 1000 to 1500 calories are enough to fuel the body and contain the right nutrients. That's why a low-calorie diet is not a good idea for pregnant or breastfeeding women (who need enough calories to sustain their babies as well as themselves) and athletes (who need the energy from sufficient calories to perform).

How It Works

Before you start a low-calorie diet, it's always a good idea to get a physical examination, especially if you have any health conditions such as high blood pressure or high cholesterol. Measure your body composition and decide on your goals. For example, you can measure your body mass index (BMI) and waist circumference, which are two measures other than weight that can show your progress.

Next, determine your daily calorie need. This step is going to be different for everyone and will even change for you over time. Determine how many calories you need each day to maintain your current weight, then reduce that number by 100 to 500 calories. It's okay to start slowly with just a small reduction in calories. After all, this is a lifestyle modification. If you're over-exuberant in the beginning, you might find the calorie restriction too difficult later on.

What to Eat

Compliant Foods

  • Fruits

  • Vegetables

  • Lean proteins

  • Low- or no-fat dairy products

  • Whole grains

  • Herbs and spices

Non-Compliant Foods

  • Refined carbohydrates (in excess)

  • Rich, fatty foods (in excess)

  • Sweetened beverages

Since you're reducing your calorie intake, you need to be sure that every calorie counts. That's why it's important to choose foods that are nutrient-dense. Foods with plenty of fiber also help you feel full.

Fruits and Vegetables

Most fruits and vegetables give you a lot of bang for your calorie buck, by offering less of what you don't want (calories and fat) and more of what you do (nutrients and fiber).

Lean Proteins and Low-Fat Dairy

Lean protein sources (such as grilled chicken or fish and low-fat dairy products) eliminate extra calories from fat, while still giving you the protein your body needs.

Whole Grains

Carbohydrates are not bad guys. Your body needs them. But choosing whole grains gives you more nutrients along with your calories.

Herbs and Spices

Use them to add flavor to your food without adding fat and calories. (Just watch your sodium intake.)

Refined Carbohydrates (in Excess)

No foods are completely off-limits in a low-calorie diet. But if you use up your daily calorie allotment on simple carbs, you risk missing out on important nutrients—and feeling hungry again quickly.

Rich, Fatty Foods (in Excess)

Consuming a lot of oil, butter, sugar, cheese, and fatty cuts of meat is another way to use up your daily calorie intake in a snap (and regret it later). The same goes for sweetened beverages, which can add up to a lot of calories very quickly. It's okay to use artificial or non-nutritive sweeteners to reduce your calorie intake; however, you need to focus on good foods and not sugar-free junk foods.

Still, you may want to allow yourself 100 to 150 fun calories each day for a piece of candy, a few chips, or another favorite treat. Just be sure to watch your portions so you don't inadvertently eat too much. You can also choose healthier treats instead of junk food, such as dark chocolate or a small glass of red wine— both contain antioxidants that may be good for you.

Recommended Timing

You have the freedom to consume your calories whenever it works for you. But you may find it's easier to stick with a low-calorie plan if you spread your calories out fairly evenly throughout the day.

Resources and Tips

In order to count calories, you'll need to know how much food you're eating at each meal. Start with a kitchen scale and some measuring cups and measure out all your servings, at least until you feel comfortable estimating your portions visually. Remember that your beverages may contain calories too, so you need to measure what you drink.

You'll increase your chances of success if you keep track of all the foods you eat. Keep your food diary in a notebook or with an app such as MyFitnessPal or the one included with a fitness monitor such as Fitbit, or an online diet site. These can keep track of your calories and also grade your daily diet for nutritional value. A food diary also allows you to see habits that may interfere with weight loss, such as using food for comfort or as a reward.

These examples of low-calorie menus give you an idea of the kinds and amounts of foods to eat.

Pros and Cons

Pros

  • Accessible

  • Effective

  • Safe

Cons

  • May cause increased appetite

  • Requires careful planning and tracking

  • Not for everyone

Pros

Accessibility

A low-calorie diet does not rely on specific, specialty foods or supplements. It requires regular, real food that is available at any supermarket (although you may want to look for low-calorie and low-fat versions of some foods, such as dairy products).

Effectiveness

If followed carefully, this diet is generally effective, especially in the short term. Maintenance will require a lower-calorie diet than prior to the weight loss. When your weight goes down, your calorie requirement decreases, and you need to adjust your calorie intake. Remember the goal of a low-calorie diet is good health.

Safety

This diet's safety also depends on how carefully it is followed, which is why medical supervision and advice is recommended. A doctor or nutritionist can help you make sure you are getting the right mix of nutrients and enough calories to keep you safe and healthy.

While this diet has a lot to recommend, it comes with several caveats. The diet is only as safe and effective as the person following it. Those who use this diet need to get good advice and adhere to that advice carefully.

Cons

Hunger

When you consume fewer calories than you are used to, you are going to be hungry. A low-calorie diet can backfire if you can only stick to it for a short time and then rebound with weight gain. It can help if you eat slowly and chew your foods thoroughly, enjoying each mouthful. Also, drink plenty of water. Your body needs fluids, and water contains no calories. Add lemon or lime slices for a bit of flavor.

Practicality

Following a low-calorie diet as recommended by a medical professional means a good deal of planning and careful tracking of the calories you consume. Unlike a very low-calorie diet (in which you only consume meal replacements), on a low-calorie diet you make the decisions. You are in charge of your own food intake—the what, the when, and the how much.

Appropriateness

For some people, a low-calorie diet is not advised. That's why it's good to check with your doctor before starting this or any weight-loss plan. Women who are pregnant or breastfeeding should not follow a low-calorie diet, for example.

How It Compares

At its heart, a low-calorie diet is the most simple way to look at weight loss: Create a calorie deficit, and weight comes off. However, the make-up of those calories matters a lot.

USDA Recommendations

As a general rule, the USDA suggests a 2000-calorie-per-day diet for weight maintenance, and 1900 or fewer calories per day for weight loss. The low-calorie diet takes this farther by reducing daily calories to 1500 or fewer. It does, however, recommend a balanced nutritional intake in accordance with USDA guidelines.

Since calorie needs can vary greatly, determine yours (including how many you should cut to reach a weight loss goal) with this calculator.

Similar Diets

Many diets are low-calorie plans with a twist or tweak to make them memorable or easier to follow (such as the HCG Diet). Very low-calorie diets, even though they sound similar, are quite different because they are prescribed by a doctor and you do not consume any food, only meal replacements.

Low-Calorie Diet

  • How It Works: Reduce daily calorie intake enough to induce weight loss. The challenges are to manage appetite and to keep nutrition in balance by choosing nutrient-dense foods.
  • Types of Food: There are no prescribed must-haves or must-avoids, but for greatest success, people who follow this diet need to focus on eating fruits, vegetables, lean proteins, and whole grains.
  • Safety: This diet is generally safe if it is followed carefully and, ideally, recommended by a medical professional.
  • Effectiveness: Some research shows this type of diet can help overweight people lose weight.
  • Sustainability: For long-term success, this diet requires lifestyle changes and added exercise. After you lose weight, your body requires fewer calories, so you can't go back to eating the way you did prior to starting the diet.

Weight Watchers

  • How It Works: Instead of tracking calories, people who use Weight Watchers track SmartPoints according to a daily allowance. Foods that are lower in calories and high in nutrition are generally lower in points, so users are steered toward a low-calorie, nutrient-dense diet.
  • Types of Food: Nothing is off-limits, but to follow the plan, you'll need to track your choices carefully and learn how to budget your points. For example, if you eat a breakfast that is high in points (say, a cheese omelet with a side of sausage), you will need to eat low-point meals and snacks for the rest of the day to stay within your points allowance.
  • Safety: This diet is generally safe unless there are underlying medical complications.
  • Effectiveness: Weight Watchers works for most people when they follow the plan carefully.
  • Sustainability: This plan helps you learn to eat for weight loss and long-term maintenance, favoring lower-calorie foods while still maintaining nutritional balance. It costs about $20 per month during the active weight-loss phase.

Diet-to-Go Balance Plan

  • How It Works: Like other meal-delivery services, such as Jenny Craig and Nutrisystem), Diet-to-Go takes the planning and preparation out of a low-calorie diet. People on this plan purchase between 10 and 21 meals per week. These meals are calorie-controlled and nutritionally balanced, like a low-calorie diet is.
  • Types of Food: People on this diet order complete fresh or frozen meals from a menu of options that are designed to meet both their calorie and nutrition requirements. They can replace all of their meals or make their own healthy choices for a few meals or days per week.
  • Safety: This plan is generally safe but the calorie counts are quite low. Get advice from a doctor before signing up. Diet-to-Go also has plans specifically designed for vegetarians, people with diabetes, and people who follow a ketogenic diet.
  • Effectiveness: Independent research is not available, but like other low-calorie diets, Diet-to-Go can be effective if carefully followed.
  • Sustainability: Since users of this plan are not making their own decisions about (most of) their food intake, it can be hard to sustain if you are not buying the Diet-to-Go meals.

Low-Fat Diet

  • How It Works: Once thought to guard against heart disease, a low-fat diet means cutting back fats to no more than 25 to 35 percent of daily calories.
  • Types of Food: Anything that's low- or no-fat is okay to eat. People on this diet may use fat substitutes (like margarine for butter) and avoid meat and other foods that are higher in fat.
  • Safety and Effectiveness: Doctors no longer believe that this diet will lower the risk of heart disease, cancer, or obesity.
  • Sustainability: Your body, especially your brain, needs a certain amount of fat to function. Eliminating or greatly reducing fats is hard to sustain because you may not feel full if you do not get enough fat in your daily diet.

A Word From Verywell

"Low-calorie diet" is a broad term that could encompass a lot of kinds of food and even a wide range of calories. Taking in fewer calories than you burn is an effective way to lose weight, but following this diet is not necessarily simple or easy. Do your research ahead of time and speak to a doctor or nutritionist to help you get you started. This will boost your chances of succeeding safely.

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