Advanced calorie deficits (Fair Warning - long post)

SHBoss1673

this really is for the more advanced or "sciency" person, I wasn't joking. This post is for those who understand the human metabolic system and are willing to read deeper.

Assumptions (terms I expect you to know, they may or may not be in this post, but they should be known to understand everything)

TDEE
BMR (the real definition)
Metabolic Rate
Adaptive Thermogenesis
Catabolism
Anabolism
Glycogen
Lipogenesis/Lipolysis
Metabolic homoeostasis
ATP (Adenosine TriPhosphate)
Mitochondria (and their function)


So we all know the well used term "calories in vs. calories out" right? For the most part, it's relatively accurate. It's the basis for most weight loss and more importantly fat loss. Defined in a more scientific manner it's the point where calories consumed is lower than TDEE. Sounds simple and easy right? Just eat less than you burn in a day and you lose weight. One Hundred percent accurate. This is a statement of fact, cannot change, there's no argument, you can't make one. It just works.
So why all the fuss? Why do people have such a hard time with weight loss if it's really that easy. Well, I'll tell you, it's because calculating TDEE is harder than you think. TDEE isn't some set number that's exactly the same every day or for every person based on some very limited number of physical facts, it's ever changing, it's different for everyone, even those who have identical statistics can be dozens or hundreds of calories different in their TDEE. Why? Genetics people, genetics.
You can copy a workout exactly, you can copy a diet plan exactly, you can have the same amount of stresses each day, you can exist in the same external temperature, sleep the same amount...etc. If you have different genetics than another person, even given all of the above, you can still fail at weight loss (or succeed) where another won't. This is why I preach knowledge of your
own body so heavily. This is why I am so adamant about tweaking your eating to fit you. Test, analyze, modify, retest, repeat until you are spot on target.
This site is great, perfect for a person to start trying to lose weight. But as we progress through the stages of weight loss, it becomes harder to estimate how many calories you need to reach metabolic homoeostasis and therefore to predict what you need to reach calorie deficit without going to far and entering into a state where the body will recognize a constant and high calorie deficit and compensate by lowering overall calorie consumption and ramping up fat storage (commonly known as starvation mode but more accurately known as adaptive thermogenesis or the famine response).

Here's some of the pieces of the puzzle that are needed to keep a consistant weight loss srategy without seriously eating into your lean mass stores or entering into that dreaded "starvation mode" mentioned above.

- The less fat you have available, the harder it is to keep a consistent deficit.
Why: Fat is NOT your body's preferred fuel. Even though fat has far more calories per gram, the type of calories are more difficult for the human body to convert to ATP. Adipose fat first needs to be liberated from the lipocytes that contain it and converted to glycerol (and some free fatty acids use directly by cells) using the process called lipolisys. Once converted, those gycerol compounds then need to be cleaved into their component glucose molecules in the liver and kidneys where they can then enter the glycolysis and gluconeogenesis pathways(the same as carbohydrates). As you can see, this is a far more expensive process calorically than the carbohydrate metabolism. It also takes far longer to acheive, which precludes fat from being the fast acting energy source humans need, especially in times of high stress (like exercise). Back to the original question, because fat isn't the primary fuel source of the human body, only a small percentage is used when the body needs energy. Like any efficiency engine, the human body refuses to use less efficient energy until absolutely necessary. It will continually draw small amounts of fat when necessary to suppliment regular caloric needs, but never (except in one specific condition we will talk about later) will it recognize fat at the primary fuel source.

- A calorie is not a calorie, thus calories in vs. calories out is only "kinda" true.
A fat calorie is more expensive to use, it also takes longer to deliver and burn and cannot be delivered in a usable form to where it is needed as quickly as a carbohydrate can. Because of everything stated above, it should be obvious now why trying to force the body to use only fat as a fuel source is a risky proposition. It's possible, but you must be perfectly balanced to do this. A much better way is to eat the correct number of calories to keep your body "thinking" it's got plenty of energy, then use exercise to elicit that deficit we all want, which forces the body to pull small amounts of fat to make up the difference while still having plenty of "fast" energy (in the form of carbohydrates) to fuel the exercise itself. Things that require a slower trickle of energy like breathing, walking, doing the dishes, sweeping the floor...etc. (very low stress activities) can be supplemented by fat. In every study done that I've ever read (and that's hundreds), fat energy isn't tapped into by the moderate to high level activity until at a minimum the 15 minute mark, and most not seeing fat reserve usage until well after 30 minutes, see my
above description of fat metabolism to understand why. For the record, protein has a similar (but slightly different) pathway to energy.

- Yes, fat and protein can be used as primary fuel sources, but it's not how your body wants it.
Ketogenesis, or more as it's more commonly known, "low carb", is essentially starving your body of fast acting fuel and forcing the citric acid (Krebs) cycle into overdrive to produce the glucose needed to keep energy levels up. Ketones are not a preferred source of fuel, they can, however, be used after a more lengthy and expensive process to be converted to fuel. Cell mitochondria use Ketones in a similar but less effective manner. The major issues with Ketogenesis are 2 fold. First is that it takes longer to convert to usable energy in the body, thus precluding many from using this method during High Intensity cardiovascular activity such as HIIT training. Second, because of the by products released, it can stress the kidneys and liver higher than normal, carbohydrate heavy metabolic pathways. While in an healthy adult this is usually not an issue, if there is a history or condition in these organs, severe problems can develop. Also to note that these activities cause water to be stored differently in cells and dehydration is a concern if water is not monitored closely. Ketogenesis is not for the faint of heart and requires a thorough knowledge of your body and a dedication most just don't have. Yes, initial weight loss in Ketogenesis is fast, but that's mostly because of the loss of up to 15 lbs of water, which is usually immediately replaced when
carbohydrates are returned to the body in any substantial and sustained amount.

- Whether you want to believe it or not, starvation mode is real
Many people may have the wrong idea of what starvation mode is, but that doesn't make it false, it makes their concept of it false. It's up to us as intelligent human beings to combat misinformation where ever we can. That means when someone spouts something wrong or silly about starvation mode. Speak up. But do it respectfully, and provide not just a response, but proof. There's plenty out there I can give you tons of studies if you need them. But just talking about the metabolic processes surrounding this state should be enough( no studies needed, these are facts about the body, not up for debate). What starvation mode isn't: it has nothing to do with 1200 calories, it doesn't happen after 1 day of not eating, and it is NOT starvation (two completely separate terms), starvation is a state, starvation mode is a process. Yes someone in prolonged, deep starvation mode can eventually starve, but except in the case of complete absence of food, starvation istself is extremely rare and someone giving you case studies on starvation to prove points on starvation mode are only showing their scientific ignorance.
Starvation mode IS, in it's simplest form, your body's metabolic processes recognizing, over the course of days or more likely weeks, that it's receiving far fewer calories than it needs. This triggers two major functions. First, when in starvation mode the body will reduce energy consumption wherever it can, starting with the least important (in it's opinion) functions first. Second the body will use any extra calories it can find and store them as fat. So when someone says starvation mode is a myth, please try to explain that it's not a myth, it's just difficult to prove, and you can't just blithely say someone's in that state without some serious analysis.

Conclusion:
All this being said, what's the point? Well the point is to get you, the informed human, thinking about more than just calories in vs. calories out. If you're struggling to lose weight. Do some really thoughtful analysis, figure out what area you're probably lacking in, tweak your routine or diet then give it TIME to let your body adjust. Then re-analyze and decide whether it's working, if not, keep tweaking. Use your knowledge. Don't become frustrated with the process, treat it like a challenge. Knowledge will eventually allow you to succeed.


Hope this is useful to someone. Feel free to comment, question, even debate.

Regards

-Steve H.

MamaRandall

Excellent post and read!!! I always have enjoyed your posts and knowledge. Thank you for sharing!

SezxyStef

in for later after I have digested what I just read...not sure I totally agree with all of it. Will weigh in later.

jamesday100

"Yes, initial weight loss in Ketogenesis is fast, but that's mostly because of the loss of up to 15 lbs of water, which is usually immediately replaced when
carbohydrates are returned to the body in any substantial and sustained amount. "

You have to be kidding me. That is 7 kg of water. When I did a ketosis based diet my weight fluctuated by 1-2 kg max!

SHBoss1673

"Yes, initial weight loss in Ketogenesis is fast, but that's mostly because of the loss of up to 15 lbs of water, which is usually immediately replaced when
carbohydrates are returned to the body in any substantial and sustained amount. "

You have to be kidding me. That is 7 kg of water. When I did a ketosis based diet my weight fluctuated by 1-2 kg max!

note the "up to". How much will depend on how much lean mass you have along with a host of other conditions, smaller people will fluctuate less.

WBB55

What a great post. I think one of the things that people find hard to measure/compare is how much incidental movement they make. I have a "naturally thin" friend, and by this I mean he seems to be capable of eating 4000 calories most days and not gain weight. But when I started paying attention, here's what I noticed. I spent a long period of time with him once, and the day and the day after he would eat like a madman, he would hardly ever sit down. He would always stand when he told stories and very imperceptively hop from one foot to the other. And when he was seated, he was swaying back and forth and using his arms a lot. On the days he only ate 2500 calories or so, he'd sit more. He didn't use his arms to talk. How much of his TDEE was this incidental movement I'm sure would be harder to gauge. But it's obvious that at least part of his alleged "high metabolism" (as we might call it) when compared to his brother, for instance, was really just him never sitting down the days he ate a lot.

I think when I hear of people who claim they cut calories and cut and cut, don't realize how much of this incidental movement is slowing down in them to balance it out. And that's how some people can survive on 800 calories per day. They just don't realize how much they've stopped moving overall.

SKME2013

Thanks for the excellent post!
Stef.

Acg67

First, when in starvation mode the body will reduce energy consumption wherever it can, starting with the least important (in it's opinion) functions first. Second the body will use any extra calories it can find and store them as fat. So when someone says starvation mode is a myth, please try to explain that it's not a myth, it's just difficult to prove, and you can't just blithely say someone's in that state without some serious analysis.

Interesting, what are defining as "extra" calories?

SHBoss1673

What a great post. I think one of the things that people find hard to measure/compare is how much incidental movement they make. I have a "naturally thin" friend, and by this I mean he seems to be capable of eating 4000 calories most days and not gain weight. But when I started paying attention, here's what I noticed. I spent a long period of time with him once, and the day and the day after he would eat like a madman, he would hardly ever sit down. He would always stand when he told stories and very imperceptively hop from one foot to the other. And when he was seated, he was swaying back and forth and using his arms a lot. On the days he only ate 2500 calories or so, he'd sit more. He didn't use his arms to talk. How much of his TDEE was this incidental movement I'm sure would be harder to gauge. But it's obvious that at least part of his alleged "high metabolism" (as we might call it) when compared to his brother, for instance, was really just him never sitting down the days he ate a lot.

I think when I hear of people who claim they cut calories and cut and cut, don't realize how much of this incidental movement is slowing down in them to balance it out. And that's how some people can survive on 800 calories per day. They just don't realize how much they've stopped moving overall.

it's a good point. TDEE isn't something that can be measured by a website, it must be directly measured via a device. That's the only way to tell for sure. Categories of activity level are a guestimate only.

edit: some machines are better than others. I.E. a direct caloremitry test is the Super gold platinum standard as it's a closed system that measures heat, but it's a giant pain in the *kitten* and very expensive, most labs use indirect calorimetry as it's slightly less accurate but still usually within 1/10 of 1 percent accurate, which is fine for most tests. and doesn't require you to be in a closed air tight clean room for hours.

SHBoss1673

First, when in starvation mode the body will reduce energy consumption wherever it can, starting with the least important (in it's opinion) functions first. Second the body will use any extra calories it can find and store them as fat. So when someone says starvation mode is a myth, please try to explain that it's not a myth, it's just difficult to prove, and you can't just blithely say someone's in that state without some serious analysis.

Interesting, what are defining as "extra" calories?

another good observation. From the body's perspective, extra calories are calories that aren't currently being used or needed. The body doesn't think in terms of a day's worth of calories, it thinks in terms of right this second, how many calories do I need, and how many do I have in the system. In reality it's a positive and negative flow of chemicals. When cells need energy they release chemicals that trigger other chemicals and organs to produce or release more energy into the blood stream, When there are more calories floating around than needed, fat cells will collect them and store them. this is obviously a very simplistic explanation but it works for this discussion. So to answer your question, whenever there's a surplus of calories in the body, that's defined as extra. In terms of Starvation mode, the body suppresses some of those chemicals because it's in it's famine response mode, thus more calories are available for storage given the same amount of calories consumed.

jenifr818

In to see if maybe later on I can understand this. Right now I'm looking at this and reacting the same way I did geometry: :explode: :sick:

priesterse

hhmmmmmm

PhearlessPhreaks

Excellent post, thank you!

Yanicka1

Bump to read later

_TastySnoBalls_

In to read later.

cbuggy75

Great post! I would have to read it a couple of times to truly understand it all. Thanks for sharing!

heybales

Nice review.

Add that the adaptive thermogenesis is usually not in reference to the expected known effects of too big a deficit, like potential muscle mass loss resulting in lower TDEE, and eating less means less TEF resulting in lower TDEE, or weighing less means you burn less moving around resulting in lower TDEE.

But the effect also mentioned above about body slowing down spontaneous or non-exercise activity, possibly big lowering of TDEE.
And just the plain effect of body getting more efficient with BMR, TEF, and TDEE, causing a lowering.
It's that last one the studies haven't shown clear evidence of how long it takes to recover from, meaning metabolism and TDEE are back up at expected level based on LBM and what you could have been if not in extreme deficit.
That's where the slipping in to maintenance can be so bad. Some grind right in to it with little weight loss the final few weeks, showing just how little their maintenance is going to be now.

Not sure how the logic works that if no loss for 3-4 weeks, and someone just decides the last 2 lbs isn't needed to be lost, how they think they can now eat 500 more daily just because MFP says maintenance is that high.

Shellz31

Thanks for posting.

Dnarules

Bumping for later

Fullsterkur_woman

Really good read. I've been logging my intake for 7 months now, in conjunction with wearing a BodyMedia Fit. I do use a scale for my food at home, to somewhat offset the inaccuracy of the nutritional info from the meals I eat from restaurants. My average daily intake has been a little more than 2000 calories. During that time I lost about 10 pounds. That tells me that at the average level of exercise I've had during this time, my TDEE was on average a little under 2200 calories, despite being told by the armband that it's over 2300. But then, that's only about a 7% error, well within the 90% accuracy claim made by BodyMedia.

The weird part is that the weight loss pretty much happened in the first three months, then I've been maintaining (not really losing inches either). The average intake was less than 100 calories fewer in, say, September, when I lost over 3 pounds, than the average for the whole time, and the average calorie burn (per the armband) was only about 10 calories per day more.

There are so many variables that go into this that it's hard to know what's going on exactly. I'd guess there has been some adaptation to the lowered intake (e.g., my hair grows really slowly). Also, the inaccuracy of restaurant food data is probably way more than enough to account for the lack of continued weight loss.

But if I wasn't so sciency, like most people aren't, I can see just how maddening it would be to be "doing everything right and still not losing weight!" I absolutely agree with one of the OP's main points, that you *have* to know your own individual body and constantly refine. All these data I've been collecting will be invaluable when I decide I'm done maintaining and ready to start losing again!

FredDoyle

Tagging post

AliceDark

Brilliant post.

Starvation mode IS, in it's simplest form, your body's metabolic processes recognizing, over the course of days or more likely weeks, that it's receiving far fewer calories than it needs. This triggers two major functions. First, when in starvation mode the body will reduce energy consumption wherever it can, starting with the least important (in it's opinion) functions first. Second the body will use any extra calories it can find and store them as fat.

It took me months and a nutritionist with the patience of a saint before I believed this was even possible, and it was an enormous struggle to get me out of the "calories in vs. calories out" midset, even though constantly reducing calories over a period of a few years was not making me lose weight and was making me sick. "Calories in vs. calories out" is probably the right answer for the majority of people trying to lose weight, but it's irresponsible to say that it's the one and only factor in play.

jofjltncb6

In...for later.

DymonNdaRgh40

Nice review.

Add that the adaptive thermogenesis is usually not in reference to the expected known effects of too big a deficit, like potential muscle mass loss resulting in lower TDEE, and eating less means less TEF resulting in lower TDEE, or weighing less means you burn less moving around resulting in lower TDEE.

But the effect also mentioned above about body slowing down spontaneous or non-exercise activity, possibly big lowering of TDEE.
And just the plain effect of body getting more efficient with BMR, TEF, and TDEE, causing a lowering.
It's that last one the studies haven't shown clear evidence of how long it takes to recover from, meaning metabolism and TDEE are back up at expected level based on LBM and what you could have been if not in extreme deficit.
That's where the slipping in to maintenance can be so bad. Some grind right in to it with little weight loss the final few weeks, showing just how little their maintenance is going to be now.

Not sure how the logic works that if no loss for 3-4 weeks, and someone just decides the last 2 lbs isn't needed to be lost, how they think they can now eat 500 more daily just because MFP says maintenance is that high.

Totally agree!

This is where I'm at. I'm still trying to lose those last few pounds as I haven't lost since October so I know I'm floating around maintenance. I'm still tweaking every little thing and trying to be patient but it's very frustrating.

I'm starting to think I may need to give my body a break from being in calorie deficit mode.

duffypratt

"Yes, initial weight loss in Ketogenesis is fast, but that's mostly because of the loss of up to 15 lbs of water, which is usually immediately replaced when
carbohydrates are returned to the body in any substantial and sustained amount. "

You have to be kidding me. That is 7 kg of water. When I did a ketosis based diet my weight fluctuated by 1-2 kg max!

note the "up to". How much will depend on how much lean mass you have along with a host of other conditions, smaller people will fluctuate less.

This is entirely true. I have lost 15lbs on a single long (85 mile) bicycle ride, and have regularly lost 8-10lbs during a 90 minute yoga class. Needless to say, this loss was almost entirely sweat.

One of the benefits of starting a low carb diet, for people with high blood pressure, is that it has an almost immediate diuretic effect which will tend to drop elevated blood pressure significantly in a very, very short time.

One thing I would add to this excellent post is that we are mainly interested in losing adipose fat, and we use the measurement of weight as a substitute. Your weight can fluctuate in the short term for other reasons, and so frequent scale readings tend to include a lot of noise along with the signal (fat loss) that we are trying to read.

dare2love81

So...to take this a step further....what, in your opinion, are symptoms or warning signs of starvation mode? How can one recognize they are in starvation mode?

ETA: Not trying to be snarky, just thought it was a good question to add to the discussion. I should also add that I have no idea what the answers to those questions are.

LoggingForLife

Thank you for this. My question is, why does the body give signals to eat, hunger pangs, when it already has stored energy that it could use first?

Fullsterkur_woman

Thank you for this. My question is, why does the body give signals to eat, hunger pangs, when it already has stored energy that it could use first?

Because, as he explained, it's costly to get at that stuff, plus, your body wants to hold onto that for when food cannot be obtained (during times of actual famine).

Think of it like this: Why would you keep going to work if you have emergency savings in the bank? Because you want to avoid dipping into that savings unless it becomes absolutely necessary.

waytobeduck

I am too sleep deprived to digest this... Bump.

LoggingForLife

Thank you for this. My question is, why does the body give signals to eat, hunger pangs, when it already has stored energy that it could use first?

Because, as he explained, it's costly to get at that stuff, plus, your body wants to hold onto that for when food cannot be obtained (during times of actual famine).

Think of it like this: Why would you keep going to work if you have emergency savings in the bank? Because you want to avoid dipping into that savings unless it becomes absolutely necessary.

Ahhh. Thank you.

eazy_

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