500 CALORIES/DAY pros and cons??

geekyjock76

Just curious...many people are saying the OP won't lose any fat from doing 2 days at 500 calories. However, if her maintenance intake is 2000 calories (for example), wouldn't that put her at a 3000 calorie deficit...rendering her nearly a pound lost? I am not advocating that, but 2 days doesn't seem too extreme.

edited...i said pounds when i meant calories

One can only burn a limited amount of fat per day and it's based on total fat mass. From her previous posts, it doesn't seem like she has much to lose meaning she may already be at an average or low level of fat mass as is. A simple calculation to determine the limit of energy transfer from fat stores is: total fat mass (lbs) x 31 calories. For example, let's say she has 30 lbs of total fat mass. Thus, her max deficit window whereby fat oxidation occurs is 930 calories below maintenance. If her TDEE is 2000, then fat oxidation will only occur by eating <2000 to 1070 calories. However, not all of this 930 calories will come from fat mass - some may indeed come from lean mass even if it's a small and insignificant amount. Any energy expenditure below this limit will come from sources other than fat stores. So if she only eats 500 calories for two days, then she will be under her limit by 570 calories each day whereby those calories will come from non-fat stores.

rosemary98

Just curious...many people are saying the OP won't lose any fat from doing 2 days at 500 calories. However, if her maintenance intake is 2000 calories (for example), wouldn't that put her at a 3000 calorie deficit...rendering her nearly a pound lost? I am not advocating that, but 2 days doesn't seem too extreme.

edited...i said pounds when i meant calories

One can only burn a limited amount of fat per day and it's based on total fat mass. From her previous posts, it doesn't seem like she has much to lose meaning she may already be at an average or low level of fat mass as is. A simple calculation to determine the limit of energy transfer from fat stores is: total fat mass (lbs) x 31 calories. For example, let's say she has 30 lbs of total fat mass. Thus, her max deficit window whereby fat oxidation occurs is 930 calories below maintenance. If her TDEE is 2000, then fat oxidation will only occur by eating <2000 to 1070 calories. However, not all of this 930 calories will come from fat mass - some may indeed come from lean mass even if it's a small and insignificant amount. Any energy expenditure below this limit will come from sources other than fat stores. So if she only eats 500 calories for two days, then she will be under her limit by 570 calories each day whereby those calories will come from non-fat stores.

thank you. I appreciate your explanation. also, do you determine fat mass by body fat measurements?

Also, an answer like yours is very helpful, and I wish someone explained that to OP initially. because just telling someone it is a stupid idea doesn't hold a lot of weight (pardon the pun), but understanding why it is a bad idea (or at least not a good idea) is helpful. But apparently OP has posted similar posts, so maybe someone did explain this to her.

mommabenefield

Just curious...many people are saying the OP won't lose any fat from doing 2 days at 500 calories. However, if her maintenance intake is 2000 calories (for example), wouldn't that put her at a 3000 calorie deficit...rendering her nearly a pound lost? I am not advocating that, but 2 days doesn't seem too extreme.

edited...i said pounds when i meant calories

One can only burn a limited amount of fat per day and it's based on total fat mass. From her previous posts, it doesn't seem like she has much to lose meaning she may already be at an average or low level of fat mass as is. A simple calculation to determine the limit of energy transfer from fat stores is: total fat mass (lbs) x 31 calories. For example, let's say she has 30 lbs of total fat mass. Thus, her max deficit window whereby fat oxidation occurs is 930 calories below maintenance. If her TDEE is 2000, then fat oxidation will only occur by eating <2000 to 1070 calories. However, not all of this 930 calories will come from fat mass - some may indeed come from lean mass even if it's a small and insignificant amount. Any energy expenditure below this limit will come from sources other than fat stores. So if she only eats 500 calories for two days, then she will be under her limit by 570 calories each day whereby those calories will come from non-fat stores.

Letje_Lux

It won't hurt you, but the biggest risk is triggering a binge.

Ill say this simply


Rather shut up

The OP isn't going to die from eating 500 calories for 2 days. But it very will likely end in a binge, probably before 2 days are over.

kristen49233

ETA: i'm not a nutritionist or trainer or phd in metaphysics etc, this is just what i believe I've learned and LITERALLY the only thing that makes sense

And a 5 lb weight loss over a year makes you an expert?? Always amazes me how the "newbies" or those with little losses feel the need to offer up "expert" advice--sarcastic or not!

Sandytoes71

Its just two days people. She will be fine if its just two days, geez.

mommabenefield

ETA: i'm not a nutritionist or trainer or phd in metaphysics etc, this is just what i believe I've learned and LITERALLY the only thing that makes sense

And a 5 lb weight loss over a year makes you an expert?? Always amazes me how the "newbies" or those with little losses feel the need to offer up "expert" advice--sarcastic or not!

Hahaha kristen youre so funny, :laugh:

I'm not a newbie by any means, and you dont know my situation or my history over this past year or the year before. You dont know what my losses have or havent been, and whether or not I've had any medical setbacks.
That being said I'm not about to justify to you why I feel I can say what I say, never mind that it makes total sense..... NICE try though .. you cant always trust how the numbers line up.... or maybe you missed that comment

I believe the thread is addressing OP's question, not the losses, gains, 'newb' status, or history of the responders.

But good on ya for losing 47lbs *high five*

SLLRunner

I'm only have 500 calories for 2 days, so is that okay?? Apparently muscle loss kicks in on day 3..

No, that is not okay. It's unhealthy.

What do you mean muscle kicks in the third day? Muscle is built from weightlifting at a surplus, not starving yourself for two days.

BlueBombers

Just here for the entertainment :smokin:

SLLRunner

Its just two days people. She will be fine if its just two days, geez.

It doesn't matter. Eating 500 calories a day is not healthy, it's drastic and unhealthy. That's is twice below anyone's BMR.

Besides this, you starve yourself for two days, start eating normally, and then you gain it back. Where's the health in that?

mommabenefield

Its just two days people. She will be fine if its just two days, geez.

It doesn't matter. Eating 500 calories a day is not healthy, it's drastic and unhealthy. That's is twice below anyone's BMR.

Besides this, you starve yourself for two days, start eating normally, and then you gain it back. Where's the health in that?

This

JustYandy

Well I went to jail over a weekend this last summer and ate about 500 calories a day because the food was so gross I couldn't stand it.I lost 1 lb a day and never gained it back.(Total 5 lbs)I didn't do much in jail read alot barely could walk back in forth in my cell no energy ,but the food was so bad I have to meditate...Hope I never go there again.

msf74

What do you mean muscle kicks in the third day?

I'm guessing she means muscle atrophy starts becoming an issue after 72 hours of fasting.

mommabenefield

@OP :yawn:
what no cat gifs yet? Ok, I'll pop back later...

I just had to fulfill this wish - its my duty

CowboysFromHell

Wow, you sure did stir up a **** storm here! 2 days you should be fine, it will probably be difficult after binge eating for a while, but it wont harm you. Try not to weigh yourself while doing it, because it's mostly water weight. But eating less will make your stomach smaller so you get full on little over time!

SLLRunner

There must be something you can do with your life apart from making ridiculous posts on myfitnesspal? It's a cry for help but we can't help you. All the best with everything.

why would you post if you didn't want to help then.

thanks anyway..

Because of this:

3. No Promotion of Unsafe Weight-Loss Techniques or Eating Disorders

a) Posts intended to promote potentially unsafe or controversial weight loss products or procedures, including non-medically prescribed supplements or MLM products will be removed without warning.
b) Profiles, groups, messages, posts, or wall comments that encourage anorexia, bulimia, or very low calorie diets of any kind will be removed, and may be grounds for account deletion. This includes positive references to ana/mia, purging, or self-starving. Our goal is to provide users with the tools to achieve their weight management goals at a steady, sustainable rate. Use of the site to promote, glamorize, or achieve dangerously low levels of eating is not permitted.

Which is quoted from here: http://www.myfitnesspal.com/welcome/guidelines

Besides this, eating 500 calories is ridiculous.

Cinflo58

This sounds like intermittent fasting which btw not only healthy but clinical studies have shown that it does not decrease BMR. You can eat whatever you want as long as it's < 500 calories or <25% of your TDEE.

Skeptics can read these:

1. Collier R. Intermittent fasting: The science of going without. CMAJ. 2013;185(9):E363-4. doi: 10.1503/cmaj.109-4451; 10.1503/cmaj.109-4451.
2. Fontana L, Meyer TE, Klein S, Holloszy JO. Long-term calorie restriction is highly effective in reducing the risk for atherosclerosis in humans. Proc Natl Acad Sci U S A. 2004;101(17):6659-6663. doi: 10.1073/pnas.0308291101.
3. Halberg N, Henriksen M, Soderhamn N, et al. Effect of intermittent fasting and refeeding on insulin action in healthy men. J Appl Physiol (1985). 2005;99(6):2128-2136. doi: 10.1152/japplphysiol.00683.2005.
4. Harvie MN, Pegington M, Mattson MP, et al. The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: A randomized trial in young overweight women. Int J Obes (Lond). 2011;35(5):714-727. doi: 10.1038/ijo.2010.171; 10.1038/ijo.2010.171.
5. Heilbronn LK, Smith SR, Martin CK, Anton SD, Ravussin E. Alternate-day fasting in nonobese subjects: Effects on body weight, body composition, and energy metabolism. Am J Clin Nutr. 2005;81(1):69-73.
6. Johnson JB, Summer W, Cutler RG, et al. Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma. Free Radic Biol Med. 2007;42(5):665-674. doi: 10.1016/j.freeradbiomed.2006.12.005.
7. Mattson MP, Wan R. Beneficial effects of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems. J Nutr Biochem. 2005;16(3):129-137. doi: 10.1016/j.jnutbio.2004.12.007.
8. Van Proeyen K, Szlufcik K, Nielens H, Ramaekers M, Hespel P. Beneficial metabolic adaptations due to endurance exercise training in the fasted state. J Appl Physiol (1985). 2011;110(1):236-245. doi: 10.1152/japplphysiol.00907.2010; 10.1152/japplphysiol.00907.2010.
9. Varady KA, Bhutani S, Church EC, Klempel MC. Short-term modified alternate-day fasting: A novel dietary strategy for weight loss and cardioprotection in obese adults. Am J Clin Nutr. 2009;90(5):1138-1143. doi: 10.3945/ajcn.2009.28380; 10.3945/ajcn.2009.28380.
10. Varady KA, Hellerstein MK. Alternate-day fasting and chronic disease prevention: A review of human and animal trials. Am J Clin Nutr. 2007;86(1):7-13.


Haters gonna hate.......

SLLRunner

What do you mean muscle kicks in the third day?

I'm guessing she means muscle atrophy starts becoming an issue after 72 hours of fasting.

Must be. And, that's something we all want, right? :bigsmile:

Keiras_Mom

This sounds like intermittent fasting which btw not only healthy but clinical studies have shown that it does not decrease BMR. You can eat whatever you want as long as it's < 500 calories or <25% of your TDEE.

Skeptics can read these:

1. Collier R. Intermittent fasting: The science of going without. CMAJ. 2013;185(9):E363-4. doi: 10.1503/cmaj.109-4451; 10.1503/cmaj.109-4451.
2. Fontana L, Meyer TE, Klein S, Holloszy JO. Long-term calorie restriction is highly effective in reducing the risk for atherosclerosis in humans. Proc Natl Acad Sci U S A. 2004;101(17):6659-6663. doi: 10.1073/pnas.0308291101.
3. Halberg N, Henriksen M, Soderhamn N, et al. Effect of intermittent fasting and refeeding on insulin action in healthy men. J Appl Physiol (1985). 2005;99(6):2128-2136. doi: 10.1152/japplphysiol.00683.2005.
4. Harvie MN, Pegington M, Mattson MP, et al. The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: A randomized trial in young overweight women. Int J Obes (Lond). 2011;35(5):714-727. doi: 10.1038/ijo.2010.171; 10.1038/ijo.2010.171.
5. Heilbronn LK, Smith SR, Martin CK, Anton SD, Ravussin E. Alternate-day fasting in nonobese subjects: Effects on body weight, body composition, and energy metabolism. Am J Clin Nutr. 2005;81(1):69-73.
6. Johnson JB, Summer W, Cutler RG, et al. Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma. Free Radic Biol Med. 2007;42(5):665-674. doi: 10.1016/j.freeradbiomed.2006.12.005.
7. Mattson MP, Wan R. Beneficial effects of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems. J Nutr Biochem. 2005;16(3):129-137. doi: 10.1016/j.jnutbio.2004.12.007.
8. Van Proeyen K, Szlufcik K, Nielens H, Ramaekers M, Hespel P. Beneficial metabolic adaptations due to endurance exercise training in the fasted state. J Appl Physiol (1985). 2011;110(1):236-245. doi: 10.1152/japplphysiol.00907.2010; 10.1152/japplphysiol.00907.2010.
9. Varady KA, Bhutani S, Church EC, Klempel MC. Short-term modified alternate-day fasting: A novel dietary strategy for weight loss and cardioprotection in obese adults. Am J Clin Nutr. 2009;90(5):1138-1143. doi: 10.3945/ajcn.2009.28380; 10.3945/ajcn.2009.28380.
10. Varady KA, Hellerstein MK. Alternate-day fasting and chronic disease prevention: A review of human and animal trials. Am J Clin Nutr. 2007;86(1):7-13.


Haters gonna hate.......

:flowerforyou: Thanks for this!

While I don't recommend consecutive fast (or 500 calorie) days, alternate day or intermittent fasting is healthy and sustainable.

rb16fitness

@OP :yawn:
what no cat gifs yet? Ok, I'll pop back later...

I just had to fulfill this wish - its my duty

Hehe. Absolutely gorgeous! This has made my day :happy: