A few of the paleo bloggers have mentioned Dr Mehmet Oz’s new year’s guidelines. Oz is also in the Larry King interview with Gary Taubes (part 1, part 2). The interview is interesting because it brings in not just Oz but also Jillian Michaels.

The mainstream (Oz, Michaels) contention is that “just 100 calories a day” of extra food (or less exercise) is what causes obesity. Thermodynamics is often brought in: calories in = calories out! It’s all sciency so therefore it’s true! “Weight is an energy equation,” Michaels says.

But it’s not an independent equation. Oz kinda hints at this: exercise isn’t awesome because it burns calories, but because it builds muscle, and muscle is what burns calories. Yet cardio doesn’t build muscle (in most people it probably breaks it down). Biggest Loser is all about cardio, too. You don’t get buff and pump up your basic metabolic rate (BMR) by sitting on the exercise bike for an hour a day; you’re just burning off whatever fuel your body can find.

AND IF YOU’RE EATING CARBS, your body can’t burn fat. Carbs up-regulates insulin and down-regulates glucagon. Burning fat is very hard if your hormones aren’t cooperating. Exercise burns through any circulating blood sugar, muscles need more energy, and the body responds by releasing stress hormones, which then scavenge lean tissue for some protein to convert into energy. (And some researchers theorize that those stress hormones then lead to heart disease.) Riding a bike and running burn off your muscles and give you heart disease. A great way to burn off body fat? Not at all.

Strength (resistance) training is a great way to build muscles. The smart way. Whether you’re at a gym, doing body-weight exercises (like pushups and pullups), or something like Crossfit, you’re putting on muscles. 24 hours a day, those muscles need food. About 20% of your total BMR is muscles, so being more muscular won’t dramatically increase your daily energy expenditure, but indeed it does only take about 100 calories a day to shift to weight loss; a few pounds of muscle can do that. Maximize muscle gain by working out after a long fast; the absence of insulin and the presence of growth hormone will help you bulk up faster and more efficiently.

So more muscle tissue increases BMR, which means the negative side of the weight equation gets bigger, which means weight loss. The positive side of the equation is calories in. And this is really what Taubes was getting at in the interview: what you eat isn’t just calories; it also produces hormonal responses.

Trading one meal for another calorically equivalent food isn’t neutral. The presence of cofactors and/or anti-nutrients will change what gets absorbed, so just because you put it in your mouth doesn’t mean you’ll get those calories. The elephant in this room is the insulin response from consuming carbs. Eat carbs and you’re body won’t want to burn fat for the next four hours. Eat a meal (or snack) every 3-4 hours and you won’t burn fat til you sleep.

Well, not strictly true. Triglycerides are constantly going in and out of adipose tissue. Insulin suppresses the burning of body fat, but it doesn’t drop it to zero. It’s just much much harder. This is why the Biggest Loser contestants are able to drop so much weight — that, and at 400 pounds, an hour of exercise burns an obscene amount of calories. Reduce carbs a bit, starve yourself, and burn five thousand or more calories a day, and you’ll drop weight.

Alternately, you could drop to <20g of carbs a day, fast a couple times a week, and skip the exercise — and lose weight anyway. Avoid the antinutrients (like phytate and lectins), get a full complement of vitamins (eg A, D3, and K2 together), and you’ll be healthier in addition to weighing less.