3500??? Where Did That Number Originate?

I can't listen at work, can you give a quick précis about what the 3500 is about, please?

I can't listen at work, can you give a quick précis about what the 3500 is about, please?

Fot those of you that can't listen to this until later its a radio interview with Zoe Harcombe http://www.zoeharcombe.com/. She questions the calorie in calorie out formula for losing weight. She is saying that there is very little research that to lose a pound of fat you need to create a deficit of 3500 calories. I have to say I tend to agree with her to a point! I don't think that our bodies are that prescriptive and I believe much of it is around the quality of food!

She has her own diet The Harcombe Diet - which I haven't come across.

Its an interesting interview - worth a listen!

This also is quite an interesting read.
http://www.walesonline.co.uk/showbiz-and-lifestyle/health-and-beauty-in-wales/2010/10/05/healthy-eating-according-to-zoe-harcombe-91466-27400240/

I have long since felt that the "trick" to weight loss is all about getting the nutients that our body actually needs - I think sometimes my "food cravings" are down to my body saying I need something - and its just I don't know what I want so I overeat the wrong things.

However, I still feel that activity is essential! I think my obsity problem is down to too much processed food and too little activity!

I don't subscribe to the calories in calories out theory. Load of crap in my opinion, if it was true then if you took 10 seperate adults and gave them the exact same diet and training regime, they would lose or gain the exact same amount of weight.

I think we all know that this isn't the case, it has a lot to do with your own body and how it processes the types of food you consume and your typical lifestyle. As always, choose your food by nutrient density, employ good training discipline and you will see substantial gains quickly.

The current epidemic of obesity in the western (and also now eastern) world is down to 4 factors in my mind.

1. Sedentry modern living (office work, cars, TVs, etc)
2. The food industry (cheap & easy access to horrible, overly-processed unnatural foods namely HFCS)
3. Lack of clear information (conflicting advice & plain wrong information being taught)
4. Apathy of the individual

There is a wealth of information on the foods we need to eat for proper nutrition on this forum, the training side is pretty basic and only requires your own effort.

I nicked the below from Lyle McDonald's excellent breakdown of the Energy Balance Equation.

link: http://www.bodyrecomposition.com/fat-loss/the-energy-balance-equation.html

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The next wrench that throws people into confusion about the energy balance equation has to do with the difference in gaining or losing fat and muscle. We’ve all heard for decades that if you create a 3,500 cal/week deficit, you will lose one pound and this is what people expect to happen exactly without fail, and if it doesn’t, clearly the energy balance equation is invalid.
Did you ever wonder where that value of 3,500 cal per pound comes from?

Quoting from The Stubborn Fat Solution:

"WAT in humans is composed primarily (anywhere from 80 to 95%) of lipid. By lipid, I mean stored triglycerides (TG) which are simply a glycerol molecule bound to three free fatty acid (FFA) chains. The remaining part of the fat cell is comprised of a little bit of water as well as all of the cellular machinery needed to produce the various enzymes, proteins, and products that fat cells need to do their duty. As it’s turning out, fat cells produce quite a bit of stuff, some good, some bad, that affects your overall metabolism. For the record, one pound of fat is 454 grams and let’s assume 90% lipid on average. So about 400 or so grams are actual stored TG. When burned by the body, one gram of fat provides 9 calories so 400 grams of fat contains about 3600 calories of stored energy. Now you know where the old axiom of ~3,500 calories to lose a pound of fat comes from."

Note: WAT = white adipose tissue, the primary type of fat in the human body.

So there ya’ go, create a 3,500 cal/week deficit and you should lose one pound of fat, right? Again, wrong. There is a built in assumption in the above that turns out to not be necessarily correct but also throws a wrench into expectations about the energy balance equation. That assumption is that 100% fat is being lost when a deficit is created. Now, if you diet correctly (e.g. the way I describe in my books), this is a pretty good assumption but it’s not universally true. Often people also lose muscle and connective tissue on a diet. And the issue is that muscle and connective tissue doesn’t provide as much energy to the body as a pound of fat. Rather than 3,500 calories to break down a pound of fat, a pound of muscle provides about 600 calories to the body when it’s broken down for energy.

Let me put this in mathematical terms, to show you how the identical 3,500 calorie/week deficit can yield drastically different changes in body mass depending on what percentage of tissue you’re losing. I’m going to use the extremes of 100% fat, 50/50 fat and muscle, and 100% muscle.

Condition Energy Yield Total Weight Lost
100% Fat 3500 cal/lb 1 pound
50%Fat/50% Muscle 2050 cal/lb 1.7 pounds
100% Muscle 600 cal/lb 5.8 pounds

See what’s going on? The assumption of one pound per week (3,500 cal/week deficit) is only valid for the condition where you lose 100% fat. If you lose 50% fat and 50% muscle, you will lose 1.7 pounds in a week for the same 3,500 calorie deficit. Lose 100% muscle (this never happens, mind you, it’s just for illustration) and you lose 5.8 pounds per week.

I’d note that I suspect this is why many rapid weight loss centers advise against exercise: exercise limits muscle loss on a diet and the simple fact is that you will lose MORE TOTAL WEIGHT faster if you lose muscle.

Finally, I’d note that most obesity researchers assume a loss for obese individuals of roughly 25% lean body mass and 75% fat which would put the true expected weight loss somewhere between the 1 lb/week and 1.7 pounds per week. But I don’t feel like doing the math.

I should note that the above numbers aren’t the same as for weight gain but there are differences in the amount of energy required to store one pound of muscle vs. one pound of fat. So there are still differences and this means that the predicted weight gain and actual weigh gain won’t be identical; the math just isn’t quite the same as what I presented above.
But the critics say, it still never works out that way. Even if you account for water and the above, the math still never works out. The calorie hypothesis is still incorrect.
But they always seem to steadfastly ignore the final factor.

The Energy Balance Equation Isn’t Static

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"For the record, one pound of fat is 454 grams and let’s assume 90% lipid on average. So about 400 or so grams is actual stored TG. When burned by the body, one gram of fat provides 9 calories so 400 grams of fat contains about 3600 calories of stored energy. Now you know where the old axiom of ~3,500 calories to lose a pound of fat comes from."

-http://www.bodyrecomposition.com/fat-loss/what-is-body-fat.html

That woman is crazy if she thinks the estimated 3,500 calories = 1 pound of fat is not true. It's based on the energy constant of fat properties.