Is a Low-Calorie Diet Healthy for You?

A low-calorie diet is designed for quick weight loss. The goal is to eat fewer calories than you use each day, which helps you burn excess body fat. Limiting calories can be helpful if weight loss or disease management is the goal. However, this diet isn’t built for everyone, and many may face challenges keeping the weight off long term.

There are all kinds of low-calorie diets, but no two are the same. Though many may be similar, they often have different calorie counts, meal plans, and varying scheduled eating times. Although the details are different, they all share the same goal: eat fewer calories than you use each day.

By eating fewer calories, your body naturally utilizes stored or excess body fat, water, and other tissues (like lean muscle) to compensate for this calorie deficit, often resulting in weight loss.

Low-calorie vs a very low-calorie diet

It's important to note that there is a distinct difference between a low-calorie diet and a very low-calorie diet.

A very low-calorie diet is a clinically supervised diet plan where you eat 500–800 calories daily. Very low-calorie diets are sometimes considered for severely obese people who are managing diabetes or those preparing for major surgery or preparing for fertility treatments.

Although this diet isn’t usually the first option for managing obesity, it can be very effective in the short term when medically indicated and supervised. However, please do not use a very low-calorie diet without medical supervision, as these diets have the potential to cause long-term metabolic changes/disturbances.

A low-calorie diet is a diet plan that involves eating between 1000–1700 calories a day, depending on activity level. This diet is primarily used for steady weight loss and is not (usually) medically supervised. These are the types of diets this article will focus on.

Low-calorie diet – health risks & safety:

Potential health risks are usually associated with being too active without consuming enough calories. To avoid this, listen to your body and eat when you feel light-headed, nauseous, weak, or exhausted. Some hunger pangs and energy changes can be typical side effects of going low-calorie. However, you don’t want to make yourself sick, so eat a healthy snack when in doubt.

If followed carefully and, ideally, with a professional’s guidance, low-calorie diets are considered safe for most people. Professionals like a doctor, nutritionist, or dietician can help you make sure you’re reaching the right balance of nutrition and calories to keep you healthy and safe.

It is also important to note that calorie restriction should not be considered in those who have had or could have an eating disorder. If you think you might have an eating disorder, please seek medical care and do not make any severe dietary changes without the support of a trained professional.

7 ways to a successful low-calorie diet

Here is a list of 7 things you can do to set yourself up for success when implementing a low-calorie diet. And remember, some of these steps will take time and that is okay!

1. Preparation is key

Lowering your daily caloric intake may prove difficult if you’ve never done it before. You will need to learn food measurements, how to track caloric values and intake of these foods, and how to decipher low-calorie vs. high-calorie foods. Learning to use a food tracker app, purchasing a kitchen scale, and incorporating some other helpful tools will prepare you for the lifestyle change you are embarking on when you start a low-calorie diet. This is not the type of diet you jump into! The most successful results on a low-calorie diet are reflected in how well-prepared you are. If you have questions, you can seek out the help of your doctor or a local dietician or nutritionist.

Some tools to help set you up for success on a low-calorie diet include:

• Kitchen scale.
• Measuring cups and spoons.
• Meal planning containers of all sizes (ideally glass).
• A calorie and food tracker to make sure you’re staying on track with calories, but also making sure you’re eating enough nutrition! Your aim is to lower calories, NOT important nutrients like vitamins, minerals, and fiber.
• A calendar with reminders setting aside specific times for meal prep, tracking, and movement will all ensure you stick with your plan.

2. Patients with discomfort

This is probably one of the hardest things to overcome when changing to a low-calorie diet. When you eat less than you use every day, you will feel hungry, perhaps even moody. Your body is learning to function with fewer calories, which can result in hunger pangs, digestive discomfort, mood changes, sleep changes, and even detox symptoms (like headache and fatigue when limiting high-sugar or high-fat foods). You are also settling into a new relationship with food — which takes time. Patience is key as you shift from things you’re accustomed to, to things that are new and somewhat uncomfortable. Remember, an effective, healthy, low-calorie diet is a marathon, not a sprint, so prepare and be patient!

3. Start small

Because a low-calorie diet can include many behavior and lifestyle changes, don’t be afraid to start small. Start by downloading a tracking app and learning how to use it. So, test yourself by tracking a day of meals, then three days in a row, before attempting to do so for an entire week. After you’ve mastered the new app, you may be ready to try your hand at meal planning. There are also great meal planning apps online that can help you with this. Slowly build your skill set to support your new diet change. This ensures you succeed and see the results you’re working hard for. Small changes over time often yield better results.

4. Portion size matters

Using smaller plates and smaller utensils often helps control portion sizes, making eating less throughout the day easier. When you eat directly from a container, package, or bag, you have no real sense of how much you’re consuming, making it easy to overeat without knowing it. A study published by the National Institute of Health found that “people consistently consume more food and drink when offered large-sized portions, packages, or tableware than when offered small-sized versions.” It is our human inclination to eat more when more is available. Seeing food on your plate makes you aware of your portions and how much you eat. By proportioning your food and using a smaller plate or bowl, you are setting yourself up for success.

5. Get moving

Research has shown time and time again that diet alone is not a great indicator of health. You need to move your body every day! Exercise, movement, and an active lifestyle have been proven to increase weight loss in the short and long term significantly. The Journal of the Academy of Nutrition and Dietetics published a study that found that dieting or exercising alone was not nearly as effective as programs that combined the two. They found that “longer-term weight loss is increased when diet and physical activity are combined,” so if you’re taking the time and energy to prepare for a low-calorie diet, also be sure to incorporate appropriate movement into your plan. A low-calorie diet isn’t the time to start training for a marathon or power weight lifting; you’ll need more calories than this diet outlines to be successful with that kind of intense activity. Instead, opt for walking, yoga, or activities that help you feel energized versus exhausted. Always be sure to match your activity to your energy consumption!

6. Read labels

Cementing the habit of reading labels is a skill that can help you throughout life — not just when considering a low-calorie diet. Learning to read food labels empowers you to make better food choices. For example, you might be surprised to learn that what you thought was a single serving is actually 2 or 3! Learning about serving sizes and the contents of your food allows you to make more educated decisions when you shop and cook at home. It also makes learning to track your foods much easier and more accurate. It’s true what they say; you are what you eat, so get acquainted with what exactly is in your food and how it could be affecting both your calorie intake and your overall health.

7. Swap out high-calorie foods

Replacing or removing even the smallest things you do daily could make a big difference. For example, if you swap your morning latte for black coffee with almond milk, you save about 200 calories each day. After one week, you’ve managed to avoid consuming 1400 calories on a low-calorie diet, which is almost an entire day’s worth of calories! For some perspective, one pound of fat = 3,500 calories. Now imagine swapping that soda at lunch, a piece of candy in the afternoon, or a bowl of ice cream after dinner for something lower in calories. These alone will make a big difference in your caloric consumption, and you will see big changes sooner.

Keeping the weight off

It’s important to keep in mind that low-calorie diets have a high regain rate, meaning those who experience weight loss on a low-calorie diet often regain that weight over time. This is mainly attributed to a combination of biology and psychology. What does that mean? Well, the more we study weight, obesity, and weight loss, researchers are finding it is a very multifaceted subject.

In addition, the threshold for weight loss plateaus, and metabolism, gut hormones, and other biological factors change over time. A study published in Nutrition & Metabolism found that the way your body uses calories actually adapts over time, making a long-term low-calorie diet very difficult to stick with, as the weight will often creep back on (especially if your diet returns to your normal caloric intake).

The old belief that “calories in – calories out = weight loss” is being debunked as studies find there is more to it than calories alone. Your relationship to food, long-standing food habits, food preferences, and choices, as well as body image and other lifestyle factors (movement, stress, hydration, etc.), are ALL facets of weight loss, especially long-term weight loss. A study in the Perspective on Psychological Science found that “any successful approach to controlling weight needs to take a wider and longer-term approach than studying the intake of calories alone”.

Low-calorie diets can be a helpful way to kick-start your weight loss journey. However, it’s worth considering a more multifaceted approach to your weight loss and health goals for better, long-term results. You are a multidimensional person, and your diet and lifestyle should match!