500 Calorie Diet Results: For 5 Days My Family Ate 500 Calories, Here’s What Happened, And Why We Loved The Results

500 calories a day diet

500 Calorie Diet Results: For 5 Days My Family Ate 500 Calories, Here’s What Happened, And Why We Loved The Results

A 500 calorie diet is a very low-calorie diet that you can use to jump-start your weight loss. To achieve the best 500 calorie diet results, you need to…

500 Calorie Diet Results Overview

  1. Choose nutrient-dense foods over calorie-dense foods.
  2. Make non-starchy vegetables a top food choice
  3. Avoid sugar and processed foods
  4. Limit your eating occasions during the day to pack in more volume per meal
  5. Have your plan ready and prepare your meals at the beginning of the week

Let’s Begin…

Misery loves company, so I recruited two family members to join me in eating only 500 calories a day for 5 days.

Monday through Friday, we counted our calories, dug deep into our willpower reserves, and, at least, one of us licked our plates.

I’m a college health teacher and blogger. I tell people not to follow restrictive diets because they backfire.

So, why did I do this?

Maybe I wanted to prove a point. Maybe I was starting to waver in my convictions. Maybe I’m the coolest blogging health teacher ever.

Anyway, here’s our 500 calorie diet results including the blow-by-blow details that left us close to tears by Thursday night, and feeling fantastically slim by Saturday morning with 17 pounds lost in total.

Download Link:

Note: This is a judgement-free zone: If you’re reading this post because you waited too long to start your diet, and you need to lose weight before next weekend, you can skip ahead and get the plan we followed, GRAB THE FULL PLAN BELOW, but read my disclaimer first.

500 calorie diet plan

500 Calorie Diet Results In 3 Minutes [Video]

Here’s What’s Coming Up:

1. Why 500 Calories a Day?
2. How To Follow A 500 Calories A Day Diet
3. 500 Calories A Day Meal Plan
4. Food Prep Checklist
5. 500 Calorie Diet Results:
6. Breaking Your Diet
7. How To Follow Your Own 500 Calorie Diet

Why 500 Calories a Day?

Reason #1: Squeaking Out Nutrition

I wanted to squeeze in some nutrients, and 500 calories was as low as I could go.

I also thought there was a chance that one of the health gurus I respect,

500 calorie diet results

like Dr. Fuhrman, Dr. Hyman, or Dr. Thompson from Bright Line Eating might read this blog post, so I wanted to save a little face and not come off as a total loon.

Reason #2: Health Benefits?

As I researched the possible health benefits of low-calorie diets and intermittent fasting, I found some legitimate research.


Legitimate research = peer-reviewed medical research papers

Illegitimate research = Kim Kardashian tweeting that something works

There is a growing body of research that shows how fasting and the restriction of calories reduce inflammation, which is the secret killer that nibbles away at your joints, weakens your heart, and flairs up gut problems.

The most significant finding was the beneficial impact calorie restriction has on chronic conditions, like chronic pain, high blood pressure, metabolic syndrome, and arthritis.

More than one research paper found that calorie restriction could help people with long-term heart conditions.

And, if sticking around to see what kind of trouble your grandkids get into is important to you, restricting your calorie intake slows aging, fights dementia, and promotes longevity.

After concluding my research, I started to tingle all over. Note: If reading scientific papers makes you happy, you know you’ve spent too many years in college.

Reason #3: I Like To Challenge Myself

I can’t speak for Keith and Kelly (a.k.a. my fellow 500 calories a day guinea pigs), but I like a challenge, like when my students challenged me to create a healthy diet that cost less than a junk food diet, or when I put together my popular 7 Day Diet Challenge or Ultimate Guide on How to Lose 10 Pounds in a Month Naturally.

The bottom line for me was that I just wanted to see if I could meet this 500 calorie diet challenge without kicking the dog or displaying similar signs of moodiness.

Reason #4: Fast Weight Loss


I feel like I’ve strung you along like one of these drug commercials that tells you all the side-effect that will happen when you put this chemical in your body, and then casually mention that it might cause weight loss – Ding, Ding, Ding! I’ll take it! Who cares about the side-effects, I want a magic weight loss pill.

Believe me, eating only 500 calories a day for five days in a row does not meet the definition of a magic pill; but, yeah, it causes fast weight loss.

It could also cause side-effects that you don’t want, which brings me to my disclaimer.


(return to top of post)
Reading an article by a doctor (like this one) and following a medically supervised diet is not the same thing.

The research subjects that got those wonderful health benefits I described earlier were in medically supervised research studies. You are reading an article that follows three healthy individuals, none of which take any medication or have any health conditions. If you want to follow a restricted-calorie diet, tell your doctor first.

Here are the specifics to pass along to your doc…

How To Follow A 500 Calories A Day Diet

The name of the game is to pick foods with the most bang for the buck. You want every food to count, so here are the criteria your food choices need to meet:

  • Low calorie (Thanks, Captain Obvious)
  • Packed with vitamins and minerals
  • Have some volume to them
  • Take a long time to digest

Abiding by these rules ensures you’re getting some nutrients, and will also save some suffering on the hunger and cravings end.

When your body has what it needs, it turns off hunger and cravings.

The presence of vitamins and minerals in your digestive tract tells your brain things are going okay, and stops your brain from obsessively repeating, “Feed me,” like the big flower thing from Little Shop of Horrors.

High volume and slow-digesting foods keep your stomach busy, so it stays happy and doesn’t feel the need to call the brain and say, “send more food…NOW

Strategy #1: Foods To Eat

The following foods meet the bullet points above, so they were eaten every day:

  • Salad greens
  • Non-starchy vegetables (think veggies that go on a salad, not corn & potatoes – Here’s a list)
  • Lean protein (i.e. chicken, shrimp, tuna)

Proteins digest slower than carbs, and they don’t cause a strong insulin response, which means they help keep hunger away.

Salad greens and non-starchy vegetables are your friends when you follow a restricted-calorie diet. They are low-cal, yet add volume and nutrients, which keeps the hunger and craving switch in the off position.

You don’t want to be spending a lot of time in the kitchen this week. So, we relied on:

  • Bags of pre-washed salad greens
  • Bags of frozen non-starchy veggies
  • Pre-cooked rotisserie chicken
  • Pre-cooked shrimp

Salad, soup, and stir-fry are easy meals that work nicely on a 500 calorie diet. You’ll need to avoid high-calorie salad dressings, crackers, and oils.

In addition to the foods above, you could also eat limited amounts of oatmeal, berries, walnuts, beans, and plain popcorn. (Here’s the trick for making microwave popcorn without oil.)

Strategy #2: Foods To Avoid (a.k.a. The Things You’ll Miss)

  • Sugar (The 3C’s: Cookies, Cakes, and Candies are way too high in calories.)
  • Sugary soda and coffee drinks
  • Juice (calories consumed in liquid form will pass through your system too fast)
  • Processed Foods (pretty much anything in a box)
  • Oil (you can saute’ veggies in water for stir fry)
  • Dried fruit
  • Cheese…sniff.
  • Alcohol…sniff, sniff.
500 calorie diet weight loss

Now, many of the above foods are omitted from any healthy diet. Some healthy foods also got nixed just because of their calorie count, including most nuts, seeds, and fruits. You can rearrange your food choices to include these if you wish.

If you’re a vegetarian, you can get protein from the vegetables (a surprising amount) and swap the meat for beans. Eggs are also a possible protein source if you eat them.

Strategy #4: Drink…A Lot

Something magical happens as you get into the groove of a 500 calorie day, you start to look forward to little treats, like a warm cup of tea.

It becomes a lifeline. Something to hold in your hands that provides comfort.

Drink a lot. I found myself thirsty quite often.

It doesn’t have to be tea. We decided that any non-calorie drink was going to be allowed, so water, coffee, and diet soda were fair game.

Strategy #5: Two Daily Meals, Instead of Three…No Snacks

This eating style is not my norm. I like breakfast. I like lunch. I like dinner. But, I knew three tiny meals weren’t going to cut it, so I chose to nix breakfast.

I wanted to save my calories so that I could eat a more substantial lunch and dinner. The hope was that this would add some volume to my stomach and reduce suffering, which brings me to my next point.

There will be suffering.

Suffering is unavoidable, so plan ahead and get as much food in your belly for the allowable calories, then prepare yourself mentally.

Another point worth mentioning is that the act of eating stimulates your appetite. I would rather deal with that stimulation twice a day rather than three times, so again…breakfast got the ax.

Strategy #6: Have Everything In Place By Day One

You do not want to find yourself inside a grocery store on day three because you ran out of lettuce. No one is that strong.

Have all of your food bought and prepared by Sunday. I spent four hours on Sunday preparing the soups, chicken, taco meat, and tuna salad.

BTW, I made up a complete 5-day meal plan for you; including all of the recipes, the grocery list, and calorie counts, go here to get it.

Here’s what we ate:

500 Calories A Day Meal Plan

You can download the complete meal plan we followed here, below I share the basic meal plan.



4 cups of salad greens, 1 chopped tomato, ¼ cup onion, ¼ cup chicken (135 calories)

2 Tbsp. of very low or no-calorie salad dressing, like this one.


Zesty Quinoa Soup (70 calories/cup)

Tomato Soup (70 calories/cup)

Classic Vegetable Soup (60 calories/cup)

(The soup recipes are included in the meal plan.)

Note: you can choose a canned soup; although it will be higher in sodium, which might cause bloating. There are many varieties, so you’ll need to read labels. Look for soups that under 100 calories/cup. Here’s how to pick canned soup.



8-oz bag of broccoli and cauliflower (65 calories)

2 Tbsp. of Healthy 10-Calorie “Cheese Sauce” (see recipes).

Lean Protein:

1/2 cup chicken (115 calories)

3.5 oz. shrimp, which is about 9 medium-size shrimp (115 calories)

2 eggs (160 calories)

4 oz. of tuna (140 calories)


Coffee, tea, water, and diet soda (0 calories)

Food Prep Checklist

It’s important that you buy all of your food for the 500 calorie diet before you begin.

(You can download the full grocery list here.)

500 Calories a Day Menu
  1. Buy at least one fully cooked rotisserie chicken and pull off the meat before the week starts.
  2. Buy a platter of cooked shrimp
  3. Buy a few bags of frozen vegetables. I choose broccoli and cauliflower because it was a low-calorie option. I also bought frozen vegetables for the soups.
  4. Make the “Cheese Sauce” for the veggies. If the thought of eating plain veggies makes you gag, this will save you. [recipe]
  5. Make all three of the soups [recipes]

Strategy #7: Clean Up Your Environment

Those cookies on the counter will become your kryptonite by Tuesday; get them out-of-sight, so they are out-of-mind.

Do not overestimate your willpower. Grab a sealable container, put any junk food inside, seal it up and move it out of the kitchen.

Strategy #8: Have Stoppers In Place

A Stopper is any activity, food or drink that stops your desire to eat.

This week I relied on brushing or flossing my teeth anytime I felt a really strong temptation to overeat. These stoppers leave my mouth feeling clean and fresh, so I’m reluctant to dirty it up with food.

Here are some other stoppers that you might want to use to get the best 500 calorie diet results.

Strategy #9: Have a Hobby Ready To Go

Mental distraction will be a good thing this week, particularly during the evening hours.

I had a jigsaw puzzle set up in the living room to keep my hands and mind occupied.

Whatever you pick, try to make it something that is different than your normal routine and requires your hands and your brain (i.e. painting, video games, sewing, reading).

Strategy #10: Minimize Exercise

I recommend against heavy exercise this week because the body demands food after intense calorie-depleting workouts.

500 calories a day

And, as I point out in my post on how to lose 10 pounds in a month naturally, strenuous exercise stimulates your hunger, which we did not want.

Kelly and I did some walking, stretching or light exercise which was fine. Keith played roller hockey on Tuesday, which was a more intense workout. He was a bit worried about it spiking his hunger, but said he was fine.

Extra Points That Didn’t Fit Anywhere Else

Point #1 – Vitamins:

This 500 calorie diet is only five days, so you don’t need any special vitamin supplementation. I will be taking Omega-3 Fatty Acid and Vitamin D.

I’m hoping the Omega-3s help with vitamin absorption, and the only reason I’m taking Vitamin D is that it’s winter and I can’t rely on sunlight to help my body make Vitamin D naturally.

Point #2 – Don’t expect life to cooperate with you:

You are about to tackle a sizeable challenge, so expect that your car will breakdown, your friends will throw you a surprise party, and that annoying guy at the office will develop a new catchphrase that he repeats 27 times.

Meeting a challenge is easier when you anticipate bumps and hiccups, so expect the unexpected and your week will go smoothly.

What Happened During The 500 Calorie Diet?

The three guinea pigs:

Becky (me): 48-year-old female, cute as a button; starting at goal weight.

Keith: 55-year-old male, all-around great guy; some weight to lose.

Kelly: 20-year-old female, cute as a button and an all-around great gal; already thin, but would love to see her abs.

(I would like to acknowledge Keith and Kelly for volunteering. Their willingness to help with this project shows both their love and lack of understanding about what was coming.)

Below I provide a running journal of how we were feeling and what we thought as the week progressed. I decided to use this format after reading Nat Eliason’s epic water fasting results post.

500 Calorie Diet Results: Here’s The Week in a Snapshot:

Mental Clarity: None of us felt mentally foggy, probably because we weren’t eating junk foods that cause brain fog. Kelly felt a bit forgetful at work on Thursday, and I had a headache on Wednesday, which was unusual. Keith was steady all week.

Fatigue Level: We all felt some fatigue, but it was more of a feeling that we didn’t want to take on any heavy lifting projects. The diet didn’t seem to disrupt sleep or require us to sleep longer hours.

Hunger Level: Hunger was part of the deal. I designed our diet to include lots of volume, which did take the hunger away for a few hours after meals; however, hunger was present the other hours. 500 calories is not a lot, mentally preparing yourself for hunger helps.

Weight Loss: The weight loss was fast and impressive, especially considering that Kelly and I were already at goal weight.

In the five days:

  • Keith lost 9.2 pounds
  • Becky lost 5.4 pounds
  • Kelly lost 2.4 pounds
500 calorie diet 5 days

DAY 1 was the easiest for all of us; probably because we ate a bit more than usual on Sunday and had some reserves in our system.

DAY 2 was rough on Kelly. She felt like she was getting sick and was low on energy. She rearranged her calories to have a very small amount of chocolate and peanut butter, which made her feel better. I hated to tell her that feeling better when you eat sugar is a classic sign of sugar addiction.

DAY 3 everyone felt fairly good. Kelly rebounded a bit, and Keith mentioned that he liked the feeling of not being so full. I felt better mentally and physically than I did on day two.

DAY 4 was the hardest day for each of us. We felt fine physically, but mentally we were ready to be done.

DAY 5 we saw the light at the end of the tunnel, which boosted our motivation. It was easier to stick with the plan knowing that it was over in less than 24 hours.

500 Calorie Diet Results Journal: Our Thoughts During The Week

Day One: Monday

6:30 AM: After weighing in, I started my day with a cup of coffee.

7:30 AM: I had my first thought of eating breakfast and felt a small twinge in my stomach. I’m not physically hungry, so this is likely a habitual response.

11:30 AM: I’m hungry, and a bit shaky. I think the shakiness is due to drinking caffeine on an empty stomach.

1:00 PM: Lunch was very filling and satisfying for all of us. It was a lot of food (see the slideshow above). Everyone is feeling optimistic.

4:00 PM: Heading outside for a walk, I’ve felt great ever since lunch.

7:00 PM: Dinner. I started getting some hunger signals around 5:00, but nothing unbearable.

10:00 PM: Bed. Our impression of day one was, “That wasn’t so bad.”

Day Two: Tuesday

6:30 AM: Woke up feeling good mentally with no hungry; had some coffee.

7:15 AM: First twinge of hunger.

9:00 AM: Kelly feels like she’s getting a cold. At the gym, she walked on the treadmill and felt low on energy.

10:00 AM: I’m feeling a bit snippy, not sure if it’s due to an aggravating school project I’m working on or the fact that I haven’t eaten in the past 14 hours, but I suspect it’s a combination of both.

11:45 AM: Lunch.

2:30 PM: Kelly has taken to snacking on a single raisin. She’s not feeling strong at this point.

4:45 PM: Kelly went off the script and had a small amount of chocolate and peanut butter, which made her feel better. She’s likely experiencing some sugar withdrawal symptoms. When eating sugar makes you feel better, it’s a classic sign of sugar addiction.

7:00 PM: Dinner. Yum!

500 calories a day dinner

10:30 PM: Bed. I’ve felt very satisfied since dinner. Keith felt a bit tired today, yet he went out to play roller hockey for an hour this evening. His energy held up fine.

Day Three: Wednesday

6:30 AM: Slept fine, no better or worse than usual.

8:15 AM: I had my first thought of eating, which is interesting because it was later than usual.

12:00 PM: Lunch.

4:30 PM: Keith feels good. He likes not having the “full feeling”. Kelly’s having a better day mentally and physically. I’ve found myself drinking more diet soda more than usual, and I’ve been fighting a small headache all day. I’m wondering if the two are related.

7:00 PM: Dinner. I drank water, instead of soda all afternoon and my headache went away. Keith and I sat out on our porch on this beautiful Spring-like day; we would have loved to have had a glass of wine or a cold beer. sigh.

10:30 PM: Bed. Keith and I have been pretty even from a mental standpoint, but Kelly mentioned that her happiness level has dropped each day.

Day Four: Thursday

6:45 AM: I slept fine again, but woke up feeling hungry and wishing the diet was over.

11:00 AM: I’m hungry, but not uncomfortably so. I’ve had very few stomach growls or gurgles this whole week, which seems odd. One possible thought is that I’m not eating foods that spike and then crash my blood sugar. If you’re going to follow a restricted-calorie diet, salad and vegetables are a must.

12:30 PM: Lunch.

1:30 PM: Kelly’s feeling low on energy and felt a bit forgetful at work this morning. Keith and I are weathering the diet fine, but it’s a bit painful watching Kelly go through this. She’s certainly free to quit at any time, so I have to hand it to her for sticking with it.

5:30 PM: I feel melancholy. There’s a rainstorm coming, which always lowers my mood, but I’m sure the low food intake isn’t helping.

7:00 PM: Dinner for Keith and me.

8:00 PM: Kelly had a work meeting that went late, so she just got dinner. She’s looking forward to the end of the diet.

10:00 PM: Bed. Keith mentioned that he feels good, but has found himself thinking about food quite often today. For me, this was the hardest mental strength day so far.

Day Five: Friday

6:45 AM: Woke up after a good night’s sleep, but I’m ready for this diet experiment to be over; had some coffee.

9:30 AM: Kelly told me she dreamt about deep frying chicken biscuit pancakes and eating them :).

1:00 PM: I finally had lunch. I kept thinking about eating but put it off. It almost seems easier not to eat.

2:00 PM: Kelly feels okay physically, but just WANTS something else to eat. She’s craving fruit, and is bummed that it’s too many calories; of course, ice cream and chocolate also sound good to her but have the same calorie problem.

3:45 PM: I’m much more productive today, and feel mentally clear.

4:30 PM: Keith commented, “I really haven’t found this week difficult at all.”

6:30 PM: Dinner. Kelly saved up some calories so that she could have a small dessert. Keith and I are done eating until tomorrow.

8:30 PM: We are all counting down the hours.

10:00 PM: Bed. Kelly was very happy this evening because the diet was ending. I’ve been hungrier tonight than the past evenings, yet I feel slim, and I’m curious to weigh in tomorrow morning. Keith is steady as always.

Breaking Your Diet

There are no hard and fast rules for breaking your diet, but there is common sense.

Common sense: Have a sensible breakfast, like oatmeal with blueberries.

Not Common sense, but a common approach: Eat five cream-filled donuts.

(Full disclosure: I had my sensible oatmeal as soon as I woke up, and then followed that up with a custard-filled donut a couple of hours later. We’re all human.)

After your 500 calorie days, the best thing to keep in mind is that you pushed your body hard, so be kind to it on day six.

You might have a big event planned for Day 6, which served as your motivation for taking on this 5-day 500 calorie challenge; you don’t want to spoil the event by going into a sugar coma or sprinting to the bathroom.

Diving into a bag of Oreos will provide about 15 minutes of ecstasy, but leave you feeling so sick and mentally foggy that you won’t be able to enjoy your day.

I recommend eating a piece of fruit, some oatmeal or eggs and toast in the morning, and then giving your body, at least, an hour to process the food before eating again.

After that, you can feel free to fill your stomach; in fact, a day of overeating will restore the hormone leptin, which boosts your body’s ability to burn fat.

How To Follow Your Own 500 Calorie Diet


I laid out the good, the bad and the ugly in this post, and if you haven’t been scared off, then you’re probably ready to give it a try yourself.

I put together the diet plan that walks you through how to prepare, what foods to buy, calorie counts, recipes, and the full meal plan.

It’s all you need to do your own 5-day, 500 calories challenge. Go here to get it.

Leave a comment below to let me know your 500 calorie diet results.

About the Author

Dr. Becky Gillaspy, DC graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991. Save


52 thoughts on “500 Calorie Diet Results: For 5 Days My Family Ate 500 Calories, Here’s What Happened, And Why We Loved The Results

  1. hi, dr.becky

    so just completed the 5 day 500 calorie plan…went surprisingly well…a little hungry from time to time..but easy enough. my only criticism is that i only lost a total of 3lb. this seems very little for the effort put in . is this unusual?

  2. Did the 500 calorie,, 5 day fast. I loved the vegetable soup, and Quinoa, best I havecever had. Thank you so much for helping me get my weight on a downward slide. I lost 5 pounds.

  3. hi! im so thankful for this! weirdly, this gave me motivation even though you laid out the ugly facts lol.
    Thanks so much!! i want to use the 500 calorie diet as a boost before a long term diet plan. would you recommend this diet for 2 weeks? then to change my daily calories to about 1000.
    again thank you for this! so detailed and extremely helpful.

    1. Hi Mishal,

      This diet was a 5-day experiment. By the end, we noticed a slow down in our weight loss, which likely indicated that our metabolisms were slowing, so I do not recommend following the diet for an extended period.

  4. I thought diet soda was a problem, actually causes weight gain. I did this diet before I searched info on it – last day is today. Can feel weight loss but waiting until tomorrow to weigh in.

    I am carbo/sugar addict. I had no problem with diet, no side effects, felt great, did my usual dog walks for my dog and a few neighbors, and cleaned a condo for my neighbor. Also cleaned my own place – had lots of energy. I think if you mentally make a commitment to do it, it’s easy. I’m 77, good health.

  5. How long before the weight was put back on? Apparently eating so little calories puts the weight back on very fast and then some, because your body will grab onto every little bit of cals and fat, from food from the days it thought it was starving.

  6. I started my own 500 calorie plan yesterday without researching any plans on line. I turned 54 this year and while I have been thin all my life the weight started creeping on when I turned 50 and it seemed I could not stop it. It has finally stopped just piling on so I felt like I just needed to lose what I have gained so I can get back to maintaining. Day 1 was not as hard as i thought it would be but my food choices left me thinking I would bore myself to death after 5 days. Glad I found your post, I will incorporate your foods into my plan. If all goes well (I am sure it will) I am thinking of following the plan on a regular basis say once a month. Your thoughts? Again thank you for the post, I love seeing testimonials like this without having someone trying to sell me something.

    1. Hi Di,

      While this diet is not meant to be followed long-term, occasionally returning to a very low calorie diet should be fine as long as you are in general good health.

  7. Nice experiment and very interesting – Thank-you. Did the weight stay off all of you or did it creep back on?

    1. Hi Sharon,

      This very low calorie diet was done as an experiment, and was not meant to be a long-term strategy. We all resumed our healthy diets after the five days and maintained because of that.

  8. Hi Dr. Becky!
    I stumbled upon this article as I am looking for quick solutions before a wedding next weekend. I love that your post was very real and we can see exactly what you ate each day. I just finished day one and I feel pretty good considering I also walked for 40 min on the treadmill and went to a yoga class. Any suggestions for maintaining motivation to keep going for a full five days?

    (For some context I am 4 feet 10 inches tall and I currently weigh 122.2lbs. I would love to get down to 115lbs by the wedding but my ideal goal weight is 110lbs or lower.)

    Thanks so much!

    1. Hi Jordan,

      I find that motivation comes from having a clear goal, which it sounds like you already have! The 500 calorie plan is not a walk in the park, and when we did it, we did not exercise. I can’t say that I recommended exercising on such a low-cal diet. Make sure you’re giving your body enough electrolytes. You should take an electrolyte drink like E-lyte, especially if you’re exercising.

      1. Your meals are so healthy, lots of plants and minimally processed foods. This is the best way to eat restricted calorie. I’m planning to make the soups to keep around for snacks! Thanks for sharing your experiment, your family sounds so supportive.

  9. Love the article, and results. What do you think about staying on a 2000 calorie diet and hitting the gym 4 times a week and build muscle. I heard muscle burns fat quicker?

    1. Hi ivars, 2000 calories can work for an active person. If the emphasis is on eating high-nutrient foods that are naturally low in calories, calorie counting becomes less important.

  10. What did you do the week after your 500 a day diet? I’m always afraid to work that hard and then as soon as I up my calories to even 1500 and gain some of that weight lose back, I feel that it was a waste. I have a hard time because I work in a restaurant and I am surrounded by food all of the time. Have you all kept the weight off?
    It does sound intriguing!

    1. If you continue l eating below your TDEE you will not gain, but will lose more slowly for a while. If you continue to eat below your TDEE, you’ll continue to lose.

    1. Hi Tleah,

      So happy to hear that you found this post valuable. As for how much you can lose? I don’t know, but I know it works!


  11. I know a diet like you did wouldn’t work for me. There is no way that the other 3 here would make it very easy for me. I do like the idea of cutting way back for a couple days, especially because you said that weight loss was very good for the first few days. The trick then is, like you said, not over-indulging on the next day and completely erasing the results.

  12. Just completed 5 days and was pleasantly surprised at how much easier this was than I expected. I started at 12 st 7 and ended at 11 stone 13.8. So a nice little kick start to weight loss and added confidence from last week. My worst day was Friday night but probably because I was watching my sister drink wine ?. Otherwise I felt more awake than normal. Would recommend.. Emma.

    1. That’s a perfect testimonial, Emma! Thanks for your comment! If my conversions are right that’s a little more than 7 pounds lost in the five days, which is a great jump start!

  13. Humans are frugivores. They love fruit. They are sweet-searchers. Every cell in the human body and most of all the brain runs on sugar. Eating sugar (=which originally was coming from fruit and fruit alone) makes us happy – because we were designed to eat sugar sugar sugar (from fruit). Saying that feeling good after eating sugar is a sign of sugar-addiction to me is hillarious at best. The brain is calling and begging for sugar when undercarbed – and the reward is feeling happy afterwards. Totally natural.

    1. Hi Melanie,

      Thanks for your comment. Fruit is a satisfying part of a healthy diet. If fruit is kept as the main source of sugar, then sugar addiction and the crash of sugar withdrawal would not be a issue. It’s when we consume a lot of refined sugars and high fructose corn syrup that we run into problems.

  14. WOW! This is a really great experiment that you and your friends conducted. I can’t believe that you guys did a 500 calorie diet for five days. Here I thought that my 1100 calorie diet was hard to maintain. It sounds like it got a little rough on day five. I would be dreaming of deep frying everything by that day also! I have to agree that having a sensible breakfast in the morning is the best thing that you can do for your diet. Though I have to admit donuts are my weakness as well. This is a great article and I will have to try this 500 calorie diet challenge! It sounds like a fun (and miserable) time! Thanks for enduring the experiment and sharing. You are a trooper Becky!

    1. Hi Todd,

      Yes, you’re right “challenge” is the best word for this 500 calorie experiment. It is only for the serious dieter, but I’m glad we did it so we could show actual results, not just theory!

      Thanks for commenting!

  15. Wow, what life changing material. I love in-depth posts backed by science yet based on real life principles. Great job Dr. Becky, I am definitely going to use this information.

    1. Hi Lindsey,

      Thanks for your comment. I don’t know of a relationship between fasting and fertility, but it is something that should be addressed with a doctor before starting a restrictive diet like this.


  16. What an awesome and inspirational post! I wasn’t aware of the health benefits of calorie restriction and am especially interested in the benefits for chronic pain. However I fear that if i try this I may just kill myself or someone else from hunger!

  17. I would really love to get my parents to do this! I am going to have to send a link to this their way and try to make this happen next time I with them for this period of time. Thanks for sharing the results!

  18. This was super informative. I could probably stand to lose some weight and my hubby definitely wants to. I tried to count calories but I was told by my doc if I needed at least 1500 calories for my workout regime. My husband just about died when I was making 500 calorie meals let alone a 500 calorie day. I am going to see if he’s willing to try it! Thanks for sharing!!! www.khalilahskloset.com

    1. You do need more calories if you’re working out. We purposely reduced our exercise during the 5 day experiment. Thanks for checking out my blog and leaving a comment!


  19. I’m on the 18th day of a 19 day fast where I eat 2 meals a day, one before sunrise and the other after sunset. (It’s a religious fast–I’m a Baha’i). I felt GREAT for the first 12 days, and now I’m starting to feel depleted. But the benefits of detachment, compassion, acceptance, perspective, and trust are phenomenal. Every year I look forward to the fast because I know it will whip me into shape physically, mentally, emotionally, and, most of all, spiritually.
    Great article!
    WIth love,

    1. Hi Susan,

      Thanks for your comment! It’s hard to step out of our eating comfort zone, but when we do, so many things open up to us!


  20. Is 500 calories “fair” for each of you? I’m betting Keith weighs probably twice as much as Kelly. It seems as though 500 for him would have a much bigger impact than 500 for her. Just thinking out loud…

    1. Hi Diane,

      Yep, not fair at all :). Keith certainly had the bigger calorie deficit, which explains his big loss.


  21. Amazing. I have trouble sticking to 1000-1500 calories a day. 500? Yeeks.
    I like and follow the voluminous food tip. I make a huge salad every night for dinner. But that salad alone has at least 500 calories:)
    I have been doing Intermittent Fasting for a bit more than a year now. Love it. It was a little difficult the first week, but then I was fine. And Mercola says your body starts eating your fat when hungry. Sounds good to me.
    Wasn’t your stomach grumbling a lot when you were in bed? Mine does at much more than 500.
    But I exercise quite a bit 6-days a week. It’s part of my rehabilitation regime. Can’t skip that.
    Good job!

    1. Hi Ann,

      There was some belly growling, but I was surprised how little of that went on. The growls were probably kept under control because we weren’t doing a lot of heavy exercise, and we were eating lots of vegetables, which stayed in our stomachs longer.

      Thanks for your comment!

  22. I always get concerned about slowing down my metabolism, which I’ve struggled with over the years. You obviously felt 5 days wasn’t long enough to worry about that. When would it become a concern? I’ve actually limited most of my cut-back days to 3, for safety. Curious what you think on this topic.

    1. Hi Marnie,

      Yes, your point about a slowing metabolism is a good point and was somewhat supported by our experiment. Keith lost the majority of his weight in the first three days, and then his loss slowed. This wasn’t entirely true for Kelly or me, but I think your idea about three days being your max for “cut-back days” has some merit.

      Every body will respond differently, but I think if we would have continued longer than 5 days, we would have seen a slowing of weight loss due to our metabolisms slowing down.

      Thanks for your comment!

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