Tempted to start eating 600 calories a day to lose weight? Read about the effects of a 600-calorie diet and healthy ways to restrict calories. Before we start, check out Omo, our weight-loss app with only proven ways to drop extra pounds.

Restrictive diets are usually those that strictly limit some particular products, product groups, or calorie intake with the aim of rapid weight loss. Although they can lead to weight loss, this result is usually achieved in an unhealthy, unreasonable way.

A 600-calorie diet is an example of such a restrictive diet that limits daily calories significantly.

In this article, we explore the safety of having a 600-calorie diet, when it can be implemented as part of a healthy weight loss plan, and will also provide some 600-calorie meal plan examples. 

Is a 600-Calorie Diet Healthy?

Having just 600 calories every day can lead to fast weight loss, so it can be a very tempting option for people aiming to drop pounds and see the results quickly. 

However, eating so little would lead to water loss, glycogen depletion, as well as a reduction in both fat and lean mass, all of which play a role in achieving lower numbers on the scale.

On the other hand, 600-calorie days can be implemented as part of more balanced meal plans, where calories are cut down to this extent only a few days a week. 

For instance, some people may decide to allow themselves to eat more calories on the weekend and reduce their energy intake on the following Monday, known as ‘cheat weekends.’ This is also possible to have calorie-restricted days and cheat days during intermittent fasting. 

As long as the overall calorie intake is adequate and not restricted every day for long periods, this should not provoke any major side effects and can help achieve fat loss [1] [2].

However, you should always do this under the supervision of a dietitian or a nutritionist to ensure you meet your calorie and nutrient requirements. 

The Risks of a 600-Calorie Diet

While you may shed pounds quickly, eating 600 calories every day to lose weight may not be ideal. 

Studies have found that low-energy diets can be relatively safe for obese individuals if sustained for short periods, such as  4 to 6 weeks [3]. But having so little food long-term and without medical supervision can negatively impact one’s health. 

Here are the main risks one should expect if eating such a restrictive diet for a prolonged time:

  • Malnutrition and deficiencies [4]

  • Fatigue [5]

  • Muscle loss [6]

  • Development of disordered eating [7]

  • Increased cortisol [8]

  • Reduced libido [9]

  • Amenorrhea (loss of menstrual cycle in women) [10]

Calorie Deficit for Healthy and Sustainable Weight Loss

One important question to ask is whether consuming 600 calories a day is enough to sustain your daily activities. 

Eating 600 calories a day is very effective for weight loss. However, studies have shown that less drastic calorie deficits are a healthier way to drop weight, despite taking longer.

They found that a smaller reduction of calories would still help you lose weight while also improving health parameters, such as lean mass preservation and higher reduction in body fat [11]. 

Individuals looking to lose weight sustainably should aim for a 10-20% calorie deficit instead [12], meaning that if their maintenance daily energy requirements are 2000 calories, they should eat between 1600-1800 calories a day to lose weight.

If you aim to lose weight healthily through appropriate nutrition and exercise, you try Omo, a healthy weight loss app to set your goals and track your progress effectively. 

600 Calories a Day During Intermittent Fasting

Having 600 calories a day to lose weight can be healthy as long as it is done as part of an intermittent fasting diet plan.

There are two intermittent fasting days that imply calorie restriction to 500-600 calories – 5:2 and alternate-day intermittent fasting.

Learn more about intermittent fasting schedules and how to determine which may be best for you.

These dietary protocols have been designed to create a weekly calorie deficit by having most days where you can eat more food and a few other days in which the energy intake is drastically reduced. 

For example, in the 5:2 regimen, you pick any two days of the week to restrict your calories to 500-600 per day. In alternate-day fasting, you restrict your calories every other day.

These approaches make it more bearable to sustain a diet as you are only restricting your energy intake for a few days rather than continuously, while still achieving your calorie and nutrient requirements. 

Furthermore, planning your diet this way can be maintained for longer periods with no repercussions on your health, as you would not incur major deficits of nutrients [13]. 

The Basics of Meal Planning for 600 Calories a Day

It is essential to plan your meals appropriately when you have such a small number of calories to spread across one day. Depending on personal preference, you can opt for one bigger meal or several smaller portions scattered across the day. 

The best way to tackle hunger and malnutrition on a 600-calorie day is to consume a whole-food diet, as it provides nutrients and aids satiety. Protein should be a key component of your meals, as this macronutrient helps reduce hunger [14].

Likewise, fruit and vegetables can be used to add volume to your meals to aid satiety while also adding plenty of minerals and vitamins [15]. Lastly, you should also include fats and carbohydrates in your meals as they provide energy, but you should be wary of portion sizes. 

600-Calorie Day Meal Plans

Below, you can find some meal plan options for a better understanding of how to spread 600 calories across a day. 

3 Meals a Day

Breakfast – Protein Shake

  • 30g flavored whey isolate

  • 150g blueberries

  • 250 water

Calories

Carbs

Fats

Protein

168

17.2g

0.1g

26.1g

Lunch – Tuna Open Sandwich

  • 50g rye bread

  • 2 cups of lettuce

  • 130g cherry tomatoes

  • 120g tuna in brine

Calories

Carbs

Fats

Protein

286

27g

1g

39g

Dinner – Chicken Salad

  • 80g raw chicken breast, to grill

  • 2 cups of lettuce

  • 50g sweetcorn

  • Lemon juice and salt 

Calories

Carbs

Fats

Protein

145

5.8g

1.5g

28.8g

2 Meals a Day

Breakfast – Salmon Toast

  • 1 small wholegrain toast slice

  • 70g smoked salmon

  • 50g baby spinach

  • 1 teaspoon of mustard

Calories

Carbs

Fats

Protein

298

24g

11g

25g

Dinner – Zucchini Omelette

  • 2 eggs

  • 80g zucchini

  • 8g grated Parmesan (to add to the omelet)

  • 4 rice cakes

  • 1 teaspoon of oil for cooking

  • salt

Calories

Carbs

Fats

Protein

301

45g

15g

19g

One Meal a Day + Snack

Lunch – Stuffed Peppers

  • 2 red bell peppers

  • 100g lean beef

  • 200g cooked rice

  • 15g shredded cheddar cheese

Calories

Carbs

Fats

Protein

481

71g

10g

29g

Snack – Yoghurt Pot

  • 150g fat-free yogurt

  • 125g strawberries

Calories

Carbs

Fats

Protein

119

17.5g

0.9g

9.1g

Wrapping Up

Losing weight with a 600-calorie diet is possible, although many things need to be taken into consideration before you try it. Below you can find the main key messages about this dietary approach:

  • Eating 600 calories a day for a prolonged period will help you lose weight. However, it may come with side effects, including muscle loss, fatigue, reduced libido, malnutrition, increased cortisol, amenorrhea (in women), and possibly disordered eating.

  • Due to the risks of maintaining a low-calorie diet for long, slower and more sustainable weight loss approaches are preferred.

  • 600-calorie days can be safely adopted and more successfully implemented as part of an intermittent fasting protocol, where calories are drastically reduced only a few days a week versus continuous daily restriction.

  • When eating 600 calories, focus on eating plenty of protein and vegetables to stay satiated, but don’t forget to also include carbohydrates and fats.