Why is it safe for a super morbidly obese person to eat 800 cals a day?

nooboots

The muscle thing as well, surely the heavier you are, the more muscle you use holding yourself up I would have thought, although for those who are so heavy they cant move around, that becomes counterproductive.

150poundsofme

I was going to mention about getting the liver smaller to prepare for surgery as someone above said. Some bariatric docs want you to eat really light before the surgery to see that you can do it and adhere to the eating schedule after the surgery. My girlfriend who just had some type of foot surgery wasn't able to walk for about 3 months or so. Her friend/trainer put her on an 800 calorie diet so she wouldn't gain any weight during this time. All her doctors knew about this. No side effects.

nutmegoreo

ceiswyn wrote: »

The problem is, a) the stomach is very stretchy, so that egg-sized remaining bit can get bigger again and b) it doesn't matter if you can only eat egg-sized meals, if they're calorie-dense meals and you eat them every couple of hours.

Given that WLS patients have to be really diligent about their diet in order to keep the benefits of the surgery and minimise the risk of side effects, I do wonder why they don't just... exercise the same diligence, without the surgery part...

Anyone I've talked to about it has either said fear for their health and well-being or desperation and feeling hopeless. That's not to say those are everyone's reasons, but they seem to be common.

wannabeskinnycat

ceiswyn wrote: »

The problem is, a) the stomach is very stretchy, so that egg-sized remaining bit can get bigger again and b) it doesn't matter if you can only eat egg-sized meals, if they're calorie-dense meals and you eat them every couple of hours.

Given that WLS patients have to be really diligent about their diet in order to keep the benefits of the surgery and minimise the risk of side effects, I do wonder why they don't just... exercise the same diligence, without the surgery part...

Yes, I thought of 3 egg sized meals for the whole day And of course the stomach egg would stretch duh.

For the people on the series it was a way of breaking their eating habits so they could have normal(ish) lives. These were people who'd taken eating to the max and their legs couldn't hold their weight for longer than a minute and they couldn't complete any personal care. I suppose it's all relative and the extremely strict lifelong eating regime is worth it?

One thing I had expected to see but didn't was the involvement of mental health practitioners. I don't believe anyone intentionally sets out to cause themselves so much damage and just fixing the physical side isn't the answer. Psychiatric support for the cause of the over eating, for the damaged self esteem due to being so large and for the complex life long effects - excess skin, very restrictive diet, relationships etc, should be part of the package.

Spadesheart

It has to do with the amount of fat you have on your body. There was a study that postulated that fat can give off energy at a certain rate, meaning if you had enough on you, your body would be able to draw enough energy from your fat stores without effecting lean mass, so long as the lean mass was getting an appropriate amount of stimulation and protein.

A limit on the energy transfer rate from the human fat store in hypophagia

https://www.ncbi.nlm.nih.gov/pubmed/15615615


Essentially, this study explains the rate at which body fat can release energy, which is aparently about 69 calories per kg per day. So say you are 100 kg, with 30 kg of body fat, your daily "possible" deficit would be 69*30= 2070, or about 4 pounds a week. This rate of loss is not actually possible as there are other nutritional needs we have, but it is possible to lose that much weight from just your fat per week without metabolizing any muscle or anything else, so long as you are consuming enough to maintain your musculature.

Now its worth noting that this wasn't a rigorous research study, but instead They took data from the MN starvation experiment and extrapolated to some conclusions that they never tested or examined with another study, but this is a reasonable reason to explain why really extreme deficits with a high enough body fat is acceptable.

Long term, this absolutely isn't a healthy way to go as our body requires other nutrition other than just energy to function well, but I imagine that by the time you get put on one of these starvation diets, your health is extremely compromised and it's probably more important to just get the fat off.

heybales

The problem with that research "non-study" is indeed your commented not a research study, just analyzing data from another study.

There was a study years ago - wasn't even about diet or weight loss and I can't find it right now.
Look at pro marathoners, and looked at their rate of fat burn vs carb burn during a whole run at race pace.
So actual VCO2 measurements showing what was burned
Since carb stores are limited, and pace must be such for those to reach the end, means fat is doing rest of the energy source.
They were measuring what ratio started out and ended at. IIRC, pretty even throughout. Wanted to see if their normal training and knowledge were truly allowing them to hit the fastest pace possible and yet still stretch the glucose out, or improvements to it.

I saw that study at time during hearing about the research on the MN study - did the math on the several participant's avg 5-7% body fat on 130-140 lb body - and how much fat was supplied for that effort of a marathon.

Way more fat used than the non-study research would suggest.
Say chunky 140 lb @ 7% BF = 4.44kg x 69cal = 306 cal per day. Let's just say during the 3 hr race.

140 lb @ slowish 7:00/mile for 26.2 = 183 min = 3005 calories for that chunk of time.

That would mean only burning about 10% fat during the race for that 69 cal/kg of fat to be true - and that ain't going to happen.

As soon as I saw that I knew those researchers left something major out in their thought process to using that available data.
Think water weight from original MN study.
And just because that value was maxed reached in that non-study, doesn't mean it's max possible, as evidenced by other actual research studies.

I think I've seen several examples since their research that disproves their max value.

Spadesheart

heybales wrote: »

The problem with that research "non-study" is indeed your commented not a research study, just analyzing data from another study.

There was a study years ago - wasn't even about diet or weight loss and I can't find it right now.
Look at pro marathoners, and looked at their rate of fat burn vs carb burn during a whole run at race pace.
So actual VCO2 measurements showing what was burned
Since carb stores are limited, and pace must be such for those to reach the end, means fat is doing rest of the energy source.
They were measuring what ratio started out and ended at. IIRC, pretty even throughout. Wanted to see if their normal training and knowledge were truly allowing them to hit the fastest pace possible and yet still stretch the glucose out, or improvements to it.

I saw that study at time during hearing about the research on the MN study - did the math on the several participant's avg 5-7% body fat on 130-140 lb body - and how much fat was supplied for that effort of a marathon.

Way more fat used than the non-study research would suggest.
Say chunky 140 lb @ 7% BF = 4.44kg x 69cal = 306 cal per day. Let's just say during the 3 hr race.

140 lb @ slowish 7:00/mile for 26.2 = 183 min = 3005 calories for that chunk of time.

That would mean only burning about 10% fat during the race for that 69 cal/kg of fat to be true - and that ain't going to happen.

As soon as I saw that I knew those researchers left something major out in their thought process to using that available data.
Think water weight from original MN study.
And just because that value was maxed reached in that non-study, doesn't mean it's max possible, as evidenced by other actual research studies.

I think I've seen several examples since their research that disproves their max value.

The max value, sure, but there probably is some truth in it to explain why it's possible and healthy for the morbidly obese to have such a calorie restricted diet. Heck there was a guy in Ireland that was incredibly morbidly obese, and just literally fasted for a year, lost like 200 pounds, functioned and has no ill health effects. There is a legitimate research study about him kicking around somewhere. Without something like this, that seems like black magic. I'm guessing the rate isn't linear but has an inverse parabolic loss in potential the lower your body fat is.