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What Happens If I Eat 500 Calories A Day?

Is Eating 500 Calories A Day Worth It? You Might Be Surprised.

By: Zack Mathews

Because you’ve asked the question, “what happens If I eat 500 calories a day?”, I’ve been in the health and fitness game long enough to know exactly what you are looking for. 

You want to lose weight and you want results fast.

The question you should be asking is this, “Is 500 calories a day for weight loss effective AND safe?”

Based on current studies and what I’ve experienced helping clients from all over the world, I’m going to tell you how eating 500 calories in a day can affect your health, how much weight loss will occur at 500 calories a day, and answer more frequently asked questions.  

Will You Lose Weight If You Eat 500 Calories A Day?

The simple answer is yes.  In order to lose weight your body needs to burn more calories than you consume each day.  Since our bodies burn calories through exercise, consuming food, daily movement, and to keep our necessary body organs running properly, only eating 500 calories a day will be well less than the calories your body needs.

Because you are in such a steep calorie deficit, you’ll likely lose a lot of weight very quickly.

Although the answer is yes, there’s more to your body than just weight loss and you’re going to want to dive deep into the next section to see what will happen if you actually start eating 500 calories in a day for weight loss.

What Happens If I Eat 500 Calories Everyday?


If you start eating a 500 calorie diet you are going to start seeing many negative side effects including loss of strength, loss of muscle mass, a slower metabolism, more irritability, less energy, lower sex drive, possible menstrual cycle issues, and possibly hair loss.  Additionally, with such a rapid decrease in calories, there’s a good chance you gain all the weight back and more once you start eating a normal amount in the future.

If you noticed in the prior section I said you would lose a lot of weight, not fat.  That’s because when you do a huge calorie reduction, your body is going to lose a lot of muscle along with fat.  That is something you do not want!

Those negative side effects are pretty heavy aren’t they?

It’s very important that you speak with your doctor to see what the best course of action is for YOU.  Everyone is different and working with a professional is the best course of action you can take.

 Personally I would never recommend a 500 calorie diet for weight loss to any of my clients. 

I’ve had plenty of clients lose a great amount of weight eating an additional 1000 calories or more on top of 500!

For example, check out my awesome client Naomi!  She looks great and was able to continue getting stronger as she lost weight, all without any of those brutal side effects.

what happens if I eat 500 calories a day. Healthy women transformation
what happens if i eat 500 calories a day and exercise. healthy client transformation

What Happens If I Eat 500 Calories A Day And Exercise?

Eating only 500 calories has already been shown to be dangerous and adding exercise in is only going to make it worse.  Your workouts will not be effective because your lack of energy, and you are going to missing vital nutrients your body wants to help you with your workouts.

It’s best to stick to an appropriate calorie deficit if you want to lose weight and adjust your calories as needed.

Why Am I Not Losing Weight Eating 500 Calories A Day?


Based on my experience working with clients and studies like this one,  most people drastically overestimate how much they move each day and underestimate how much they are actually eating.  There’s a good chance you are not eating 500 calories if you are not losing weight.

It’s always important to weigh your food when tracking calories and make sure to not forget to add in little bites, handfuls, oils, dressing, sauces, and toppings you might eat.  Those things can easily add hundreds of calories to your daily total.

Here’s what you are going to want to do.

First you want to find how many actual calories you should be eating that is going to be safe and not have the negative side effects listed above.

I recommend checking out my article, Macros For Weight Loss, to give you the best breakdown of how many calories to consume.

Next, start building a meal plan that will provide you energy for your workouts, won’t make you feel miserable, and won’t affect your long term health.  These two guides will lead you in the right direction.

The Best Meal Plan For Female Weight Loss

The Best Meal Plan For Male Weight Loss

weight loss 500 calories a day

Recap Of What Happens If I Eat 500 Calories A Day

There are two main takeaways you need to know:

  1. Always consult with your doctor if you want to lose weight and are wondering what happens if you eat 500 calories a day.  I can’t stress this enough.
  2. The negative side effects like muscle loss, strength loss, low energy, libido issues, menstrual issues, and weight loss don’t outweigh the one positive side effect of quick weight loss. Your best bet is to take things slow and enjoy the process without any of those side effects.