From Dr. Kurt Harris:

"Macronutrient ratios mediate weight via hormones. Hormones drive fat storage."

http://www.paleonu.com/panu-weblog/2009/8/27/how-to-lose-weight.html

I can attest to the validity of Stephen-Aegis' statements. Eating Paleo has stabilized many things for me and enabled me to lose weight that limiting calories did not.

Peter Dobromylskyj gives the science behind this, at his blog, Hyperlipid.

http://high-fat-nutrition.blogspot.com/

We can easily accept that 'calories in/calories out' is valid while still holding that changing your hormonal balance is more important.

It's (tautologically) true that if I consume more calories than I expend (expend meaning 'use on anything other than making fat') then I will gain fat. If I consume fewer calories than I expend then (tautologically) I need to burn some calories from body stores.

The crucial points are:

• 1) My body can change the amount of energy expended.
• 2) Hormonal balance can influence the amount of energy expended.

If I normally expend 2500 calories per day, that doesn't mean that if I consistently consume only 2000 calories per day, my body won't ensure that I henceforth only consume 2000 calories per day.

Similarly, hormonal balance can alter the amount of energy available and thus the amount of energy expended. If I have low insulin I may have endless supplies of fat energy available to burn, if I have high insulin I may have no fat energy to burn, I may indeed have a caloric deficit that can only be met exogenously (from consuming more food) or from reducing the amount of calories I expend.

This is shown in a great study cited in Good Calories, Bad Calories (regrettably I don't have my copy on me), where a group of women are shown to be able to lose fat easily on a hypocaloric fat and protein diet, whereas they maintain or even continue to gain fat while eating the same or fewer calories on a carbohydrate based (and thus insulinemic) diet.

So the final conclusion: yes calories in/calories out is the ultimate factor as to whether fat is lost or gained, but hormonal balance can itself determine whether more calories go in or out. If you are burning more fat then more calories are going out, by necessity, it's an analytically true (but unrevealing) statement.

They are intimately coupled. Conventional wisdom is wrong not because calories don't count, but because calorie counting is not the whole story.

This is an extremely important point. People often make the mistake of saying that calories don't count when that is not supported by a single stick of science out there. No matter what you eat, if you eat below maintenance you will lose weight. This is indisputable and in disputing it paleos tend to destroy their own credibility as well as frame the discussion in such a way that it can never be salvaged.

The counter-argument to calorie counting is not that calories are irrelevant but that they are not the primary thing to be concerned about because your calorie intake is coupled to what your body demands you do and what your body does with your calorie intake. It's a feedback loop, not a line. Calories in - calories out = change in weight. Don't ignore either side of the equation and understand that each side effects the other.

Your energy balance still matters, it's just wrong to assume that you can fight your body over energy balance forever. You need to ensure that your endocrine system is working properly, doing its job of regulating appetite and nutrient partitioning between fat/muscle, which is why avoiding certain foods helps a lot of people. In avoiding those foods, they can avoid having to calorie count, because they allow their endocrine system to naturally regulate their appetite and fat tissue into healthy balance - which, if you're fat, requires a negative energy balance.

So. My impassioned plea to the paleo community: Don't swing the pendulum so far the other way that you never settle over the truth. Re-read GCBC and focus on the part where he talks about thermodynamics and how the trivial observation of in - out = weight change is tautological, inadequate, not incorrect.

Normalizing your hormone balance (basal & post-prandial insulin/blood glucose, TSH, testosterone/estrogen, etc) will be much more influential for weight loss than caloric manipulation.

Calories are an irrelevant measure for weight loss, as they are only meaningful in the context of the food being eaten.

One can easily come up with equivalent calorie meals that will have dramatically different effects on hormones and body composition, here are two 3000 calorie meals:

1. 880g ground bison and 450g organic valley sour cream
2. 100g bison, 30g sour cream and 27 slices pepperidge farm whole grain bread

There are also a number of 'futile cycle' mechanisms throughout the body that waste energy in a sense. Dr Eades has a good post on the subject, Thermodynamics and the metabolic advantage.

Some other futile cycles of interest are:

• Cori cycle during exercise, where lactate that travels to the liver uses 6 ATP to be re synthesized into glycogen while only producing 2 ATP during glycolysis.
• Gluconeogenesis on VLC, where 6 ATP are required to synthesize one glucose molecule, which in turn can make 36 ATP
• The mitochondrial uncouple protein UCP1 assists in dissipate energy as heat, and increases in expression during overfeeding and cold acclimation. Lauric & myristic acid also seem to trigger UCP1.

Hormones determine how much you feel like eating and how much you store and how much you burn. If your hormones are balanced, then you will feel full and stop eating at the appropriate time and the calories that you do eat will be easily availabe to be burned as fuel whenever needed. If your hormones are healthy, your muscles and body will function in a more healthy manner, you will have more energy, and your metabolism will be higher. If your hormones are balanced, then you will not eat 10 bags of pork rinds each night because you will feel full and won't want to eat too many of them.

The problem with the way most refer to calories in/calories out is that they leave out the complexities and confounding variables like where the calories go in the body. If the calories are all stored due to high insulin but your muscles are not getting enough nutrients, then you will still have cravings and feel hungry for more food. If you cut calories with remaining hormonal imbalance, you will lose stored fat but your muscles will suffer even more. That is why a diet that does not deal with the hormone problems is probably not going to be healthy or easily sustainable as long as you will be fighting cravings and hunger for the rest of your life.

In order to fix the calories in/calories out issue in a healthy way, the trick is to fix the hormone problem first. The amount of eating is not a cause, it is a symptom of the hormone imbalance. Fix the hormone imbalance and the amount of eating adjusts naturally to more healthful levels because you have fixed the cause of the desire to overeat in the first place.

Yes, your question is essentially one of Taubes' major points in GCBC. I believe it is indeed both but that i put more emphasis on controlling the hormones, then calories secondarily. I think if you take someone on the SAD, they will benefit much more by getting that insulin squared away, even if they still eat tons and tons of calories. But eventually i do concede that there is a limit to how many calories you can eat without gaining unwanted fatweight. If you eat zero carbohydrates but pound down 10 bags of pork grinds before bed for a week straight, you will gain weight. Absolutely.

Insulin. Leptin. Read Gary Taubes.

Caloric restriction does work, but not long term

Hormonal changes adjust your set point

Look for insulin and leptin sensitivity/resistance control your weight heavily.

Paleo repairs your leptin/insulin