If 3500kcal deficit = 1lb weight loss, why doesn't it work?

[Watchkeys]

I'm just curious to know what people think about this. Lots of people on here are sticking to a deficit. It might not be 500kcal per day, but some increment of that would incur some increment of weight loss, if the theory holds. Millions of people are on kcal controlled diets, and mostly, they don't work, especially not long term.

What's going on?

I find people who are militant about calorie deficit = weight loss tend to be quite ignorant about things like insulin resistance

Yes @4timesthefun , some of them are on the thread, despite the PPs like yourself who have a completely different experience, which renders the whole theory unreliable at best.

Calorie deficit leads to weight loss

Most people don't get to calorie deficit

Sone things make that hard - particularly when you have broken your body through poor eating habits

People who overcomplicate are usually looking for excuses not solutions

Can calorie deficit not lead to other things instead, though, @midgemadgemodge ? For example, the calories we use for hormonal balance or mood stability? Given that insulin discourages the body from using fat, could the body not take the calories from somewhere other than the fat, if there was a deficit?

Yours is exactly the mindset I'm interested in.

A calorie deficit will always lead to weight loss. The energy has to come from somewhere and there are only three possible sources: simple carboydrates, fats, and protein. The problem is (as I wrote in my previous post), that in sedentary individuals TEE is so low anyway that it is very hard to get into calorie deficit, and this is compounded by dieting resulting in lowering their BMR and NEAT further still, resulting in them no longer being in deficit even if they were when they start calorie counting.

I’m not convinced people think like that - I mean counting calories and expecting a steady weight loss for years. This 3500 figure seems to be a straw man referenced mainly by people who want to debunk it.

Once again, @WhatWouldJeevesDo , you don't have to be convinced. There are plenty of threads right here made my people who have been trying this approach for years, whether you are convinced or not.

@BCCoach So the body cannot compensate for a calorie deficit by using less energy on bodily systems, in your opinion? The metabolism cannot change to account for a deficit? The body can only burn macronutrients, rather than the macronutrients being turned into energy to be distributed amongst the systems? How could this be? This would mean that people on the point of starvation would be very thin, but would have perfect immune systems, clear skin, level moods, regular periods etc, wouldn't it? And we know that's not the case. Are you really claiming that fat loss is the only thing a body does with a kcal deficit?

It’s probably not as simple as whether the figure is accurate for all people in real life compared to a lab but how that knowledge is applied ie, create calorie deficit and lose weight. It might be a good start point for someone who has a lot of weight to lose. When people start losing weight, then they need to reduce calories further as they’ve now got a smaller body to maintain.

Anyway, I think a PP mentioned the original research by Wishnofsky in 1958 that created the 3500 kcal/1lb weight(fat?) loss. One area I can see this going wrong is if someone is restricting calories stupid-low like 1000 or 1200, then a lot of lean muscle will be burned before the fat especially if their protein is low.

But that wasn't the conclusion Wishnofsky came to, @PortiaWithNoBreaks

The conclusion was that one pound of human fat contained 3500 kcals?

No, it wasn't. Have you read the study?

I think we do see that calories in calories out works? People don't stick to it as sometimes it's too restrictive or leaves them feeling really hungry, I guess that's where the protein etc stuff comes in.

I stated explicitly that in sedentary individuals the body responds to calorie deficit by reducing BMR and NEAT - in fact the exact opposite of what you appear to think I wrote.

Yes, I read that, @BCCoach , which is what I'm having trouble with. Why is weight loss then necessary, in every instance? If I eat 100kcal less, why can my body not entirely compensate for that by reducing BMR and NEAT? Why will it necessarily choose to also burn fat, every time? Why will everybody's body choose to burn fat, every time, when it can just make itself less 'expensive', calorie-wise? And when we eat such a lot of sugar and flour, upping our insulin, and seriously diminishing our ability to burn fat?

It seems I'm not making myself clear. I'm saying your body DOES compensate for reduced caloric intake by reducing BMR and NEAT. This results in you either being in a much smaller deficit than you believe yourself to be in, or not in deficit at all.

But what's your body compensating for, then? It must be in a deficit to start with, to have to compensate by lowering calorie expenditure. Mustn't it? So the deficit is causing reduced energy expenditure, rather than weight loss? So the calorie deficit doesn't produce weight loss, as you said it always would?

If you do less so you are not in deficit it's you that's doing less

I'm So confused!

I did Michael Moseley's 5:2 in 2013 when it first came out.
I'd put on 3 stone. (First time I'd been really overweight)
Worked a treat. I was motivated, it suited me and I lost 3 stone in 4-5 months.
Since 2016 I've been diagnosed with T1 diabetes/IBD/Coeliac disease and food has become kinda difficult.
I had kept it off for ten years bar half a stone fluctuation but now
I've put over a stone on and I want to lose it but now I'm not sure how as v low carb sends me hypo as does 5:2.
I sit on my backside all day (work) and have no energy to exercise.
I eat fairly medium carb anyway, 60g a day or so, so going low carb high fat protein isn't a massive change.
I'll certainly cut out the chocolate (which is likely why I've put it on plus meno possibly) but due to all the above health stuff (I am collecting autoimmune diseases ) what's the answer then?

I don't/won't count calories (my life is full of counting carbs as it is being T1)
The eat well Plate advice from the NHS is about the worst thing I could do! I can't believe they promote it as part of a week long T1D course I did.
Never took notice of that one!

So you think that everyone who is on a diet is actually eating to excess? If so, how, when many are eating below their TDEE? And if not, what about the people who actually are in a deficit? That's who I was asking you about. Can their deficit be compensated for by other bodily systems reducing their energy demand, do you think? Rather than their body purely burning fat, to the exact number of calories of the deficit?

@HumourReplacementTherapy

How do you do on the other macronutrients? Do you get plenty of protein and fat? That's where the nourishment is.

The body is compensating for a reduced input by reducing its output. This avoids an actual deficit.
If it’s metabolising muscle, then you are losing weight but not fat, or not just fat.

Sorry, I'm struggling here. Reducing calorific intake can result in reduced BMR and NEAT. The result of this is that either you are not in deficit at all, or a much smaller deficit than you thought.

Worked example:
Andrea estimates her BMR to be 1500, NEAT to be 200, EAT to be 500 making for a total of 2200kcal per day.
However, in reality she's overestimated her EAT (going on what her smartwatch tells her when she goes for a lunchtime walk) so in fact it's closer to 2000kcal.
She reduces her dietary intake to 1700kcal thinking this is a 500kcal deficit but in reality it is closer to 300.
Initially she loses weight, however her body responds by reducing BMR to 1400 and NEAT to 100, meaning she is now only in a 100kcal deficit.
She's constantly fatigued, so starts skipping her lunchtime walk, meaning she is no longer in deficit.
She starts putting weight back on and can't understand why.

So a reduction in kcal eaten can lead to reduced energy given to bodily systems, rather than reducing fat. That's exactly my point. That's why I'm stumped as to why anybody would think that a certain kcal deficit would lead to a certain amount of fat loss.

If it’s metabolising muscle, then you are losing weight but not fat, or not just fat

What do you think the weight you're losing is made of, in this situation? It must be made of something, mustn't it? I can't make this make sense!

@BCCoach

Yes, I understand that people miscalculate. Do you think that that explains the obesity problem we have, as a society? Sums?

What I'm trying to get at is, if a person achieves a deficit, do they, necessarily, lose weight, or might other things happen that mean they retain their weight?

The trouble is you use the word deficit to mean theoretical deficit.
Muscle.

If you achieve a deficit, then you will lose weight because that is what the definition of a deficit is: your total energy expenditure is higher than your energy intake.

It is basically "sums", if you are not losing weight, then you are not in calorific deficit, however much you believe yourself to be. The body responds to reductions in calorific intake by reducing BMR and NEAT, but the first law of thermodynamics still applies.

The reason we have an obesity problem is because we have an obesogenic environment: we make it extremely hard for people to maintain weight, and even harder for those who wish to lose weight to achieve deficit.