What Is a Low-Calorie Diet?

Low-calorie diet

 Verywell / Debbie Burkhoff

At Verywell, we believe there is no one-size-fits-all approach to a healthy lifestyle. Successful eating plans need to be individualized and take the whole person into consideration. Prior to starting a new diet plan, consult with your health care provider or a registered dietitian, especially if you have an underlying health condition.

A low-calorie diet is a structured eating plan that restricts a person's daily caloric intake. Following a low-calorie diet typically means consuming 1,000 to 1,500 calories per day, which creates a calorie deficit that can lead to weight loss. A low-calorie diet 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 registered dietitian or doctor so that you don't restrict your calories too much or miss out on essential nutrients.

Scientists have been studying low-calorie diets since as far back as the 1980s, investigating claims that these restrictive eating plans may slow the aging process. But 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 easy. It takes planning and effort to understand and recognize hunger cues and to make sure those 1,000 to 1,500 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 growing babies as well as themselves) and athletes (who need the energy from sufficient calories to perform).

What Experts Say

"A low-calorie diet is typically between 1,000 to 1,500 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

What Can You Eat?

On the low-calorie diet, you'll want to choose healthy, whole foods that are naturally low in calories. You have the freedom to consume your calories whenever it works for you, but you may find that it's easier to stick with a low-calorie plan when you spread your calories over the course of a day.

In order to count calories, first, you'll need to know how much food you're eating at each meal. Start with a kitchen scale and 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.

Food trackers keep a daily log of your calories and also grade your diet for nutritional value. A food diary allows you to realize any habits that could be interfeinge 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:

What You Need to Know

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. It is also important to acknowledge (and get help for) any history of disordered eating. Issues can be explored and addressed with a registered dietitian or qualified therapist. 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 OK 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
  • Fruits

  • Vegetables

  • Lean proteins

  • Low- or no-fat dairy products

  • Whole grains

  • Herbs and spices

What Not to Eat
  • Refined carbohydrates (in excess)

  • Rich, fatty foods (in excess)

  • Sweetened beverages

Since you're reducing your caloric 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

Healthy carbohydrates are not the enemy—your body needs them to function optimally. Choosing whole grains over refined carbohydrates 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 caloric intake in a snap. The same goes for sweetened beverages, which can add up to a lot of calories very quickly. It's OK to use artificial or non-nutritive sweeteners to reduce your caloric intake; however, you need to focus on nutritious foods and not sugar-free junk foods.

Still, you may want to allow yourself 100 to 150 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 may 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.

Pros and Cons

Pros
  • Accessible

  • Effective

  • Safe

Cons
  • May cause increased appetite

  • Requires careful planning and tracking

  • Not for everyone

There are many benefits to trying a low-calorie diet for weight loss, but still, the eating plan has its drawbacks and may not be suitable for everyone. Review the pros and cons to inform your decision about whether this diet plan is the right choice for you.

Pros

Accessibility

A low-calorie diet does not rely on specialty foods or dietary supplements. It simply calls for real, whole foods that are 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. Long-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 caloric 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.

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.

In order to avoid hunger, aim to include high fiber foods at every meal. Eat multiple servings of non-starchy vegetables at most meals and choose high fiber carbohydrates such as whole grains and starchy vegetables like sweet potatoes.

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—what, when, and how much.

Not for Everyone

For some people, a low-calorie diet is not advised. That's why it's a good idea 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, nor should some athletes.

Is the Low-Calorie Diet a Healthy Choice for You?

The U.S. Department of Agriculture suggests a diet of 2,000 calories per day for weight maintenance and 1,500 to 1,900 calories per day for weight loss.

A low-calorie diet would reduce daily calories to 1,500 or fewer,  which may be too restrictive for some people, depending on their health circumstances. The diet does, however, recommend a balanced nutritional intake in accordance with USDA dietary guidelines.

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

A low-calorie diet is the most simple way to look at weight loss: Create a calorie deficit, and you will lose weight. However, the make-up of those calories matters a lot. It's important to adhere to USDA dietary guidelines to ensure you're still getting adequate nutrition for a well-balanced, healthy diet.

Health Benefits

While proponents of the low-calorie claim that it will lead to increased weight loss, research shows that maintaining an optimal intake of vitamins and minerals during severe calorie restriction is not feasible for most people. A diet that's highly restrictive is not sustainable or practical and could lead to unhealthy eating habits.

Health Risks

If followed correctly, there are no common health risks associated with the low-calorie diet. However, following a low-calorie diet that focuses on an eating schedule is the opposite of mindful or intuitive eating, which is often an effective strategy for health, weight loss, and weight maintenance.

Additionally, not listening to your internal hunger cues can be problematic for those who have had an eating disorder or are at risk for developing one due to factors such as body image issues.

The low-calorie diet is only as safe and effective as the person following it. Those who use this diet need to get good advice from their health care provider or a registered dietician and adhere to that advice carefully.

Similar Diets

Many diets are just variations on low-calorie eating plans with certain tweaks 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.

Here's how similar diets compare to a standard low-calorie diet:

Low-Calorie Diet

  • How it works: Reduce daily caloric 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.

WW (Weight Watchers)

  • How it works: Instead of tracking calories, people who use WW 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: WW 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% of daily calories.
  • Types of food: Anything that's low- or no-fat is OK 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

A "low-calorie diet" is a broad term that encompasses many types of food and a broad range of suggested intakes for calories. Consuming fewer calories than you burn is an effective way to lose weight, but following a low-calorie diet is not necessarily simple or easy. Do your research ahead of time and speak to a doctor or nutritionist to help you get started. This will boost your chances of weight loss success in a safe manner.

Remember, following a long-term or short-term diet may not be necessary for you and many diets out there simply don’t work, especially long-term. While we do not endorse fad diet trends or unsustainable weight loss methods, we present the facts so you can make an informed decision that works best for your nutritional needs, genetic blueprint, and budget, and goals.

If your goal is weight loss, remember that losing weight isn’t necessarily the same as being your healthiest self, and there are many other ways to pursue health. Exercise, sleep, and other lifestyle factors also play a major role in your overall health. The best diet is always the one that is balanced and fits your lifestyle.

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Article Sources
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