March 12, 2023
MS, Registered Dietitian, Former President of CT Academy of Nutrition & Dietetics
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.
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.
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]
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.
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].
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.
Below, you can find some meal plan options for a better understanding of how to spread 600 calories across 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 |
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 |
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 |
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.
This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on to make decisions of any kind. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!