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I show below this line two opposed visions of nutrition:

Vision 1:

The energy content of the food we eat, vs. the energy content we expend… this is what determines whether we gain or lose fat (fat = stored energy).

It’s called the first law of thermodynamics and isn’t even debatable.

The reason low-carb diets work so well for weight loss is that they reduce appetite and cause an automatic restriction in calories (making calorie counting unnecessary, in many cases).

There is no metabolic magic at play that overrides the first law of thermodynamics. That is not possible and trying to maintain that position simply scares intelligent and educated people away.

My summary of Vision 1:

• The energy content of the food is what matters
• Low-carb diets work because of appetite reduction
• We gain gat because we eat more than we expend. It isn’t even debatable
• There is no «metabolic magic». Saying otherwise scares intelligent and educated people away

Vision 2:

According to the “calories in, calories out” (CICO) way of thinking, obesity is simply a matter of eating too many calories.

Proponents of this often say that the types of foods you eat aren’t very important, that the caloric contribution of foods is the key.

They say that the only way to lose weight is to eat less, move more and that it is any individual’s responsibility to keep calories balanced.

A pound of fat is 3500 calories (a kilogram is 7700). If you eat 500 calories less than you burn every day, then after a week (7 * 500 = 3500) you will have lost a pound of fat.

From this comes “a calorie is a calorie” – the idea that all calories are created equal, no matter what foods they come from.

Even though it is true that obesity is caused by excess calories and weight loss caused by a calorie deficit, this is still such a drastic oversimplification that it is downright wrong.

The fact is that different foods can have vastly different effects on our bodies and go through different metabolic pathways before they’re turned into energy (1).

Just focusing on the calorie content of foods and disregarding the metabolic effects they have is a highly flawed way of thinking.

My summary of Vision 2:

• Just focusing in the energy content of the food is a flawed way of thinking
• Different foods can have vastly different effects on our bodies and go through different metabolic pathways before they’re turned into energy
• Saying that gaining weight is caused by a calorie deficit is a drastic oversimplification that it is downright wrong
• Disregarding the metabolic effect of foods is a highly flawed way of thinking

Two visions, one person

The author of both excerpts is the same person, Kris Gunnars, in two different pages of his site:

• http://authoritynutrition.com/confessions-of-a-biased-low-carb-zealot/
• http://authoritynutrition.com/debunking-the-calorie-myth/

What he once thought wasn’t even debatable is a downright wrong simplification later (I suppose he doesn’t defend both views simultaneously). And he defends both views with the same conviction. He is entitled to change his mind, isn’t he? I do not pretend to ashame him for anything, but this example teaches us that we need a critical attitude when processing information, no matter the source.

Putting that to one side, Kris Gunnars does an excellent work summarizing information about nutrition. For example:

• 10 Proven Health Benefits of Eggs
• Reasons Why Coffee is Good For You
• Ridiculous Myths About Meat Consumption and Health

A FINAL NOTE

Obesity is caused by excess calories and weight loss caused by a calorie deficit. (Kris Gunnars)

Weight loss is not caused by a calorie deficit: they are almost «synonyms». One is not causing the other, they are two ways of saying the same thing.

Let me tell you a story:

Obesity is caused […] by hormonal disorder triggered by the consumption of refined and/or easily-digestible carbohydrates and sugars. By causing insulin resistance and hyper-insulinemia, these nutrients shift the partitioning of fuel toward storage rather than oxidation, and so both increase hunger and decrease the energy expended in metabolism and physical activity. That creates a calorie excess and therefore we get overweight.

Would you summarize that story saying that a calorie excess is the cause of obesity?

I don’t say the first law of thermodynamics isn’t satisfied. In obesity there is a calorie excess, but it is not the cause of obesity. The problem is «causality»:

Obesity is caused by eating the wrong foods, what leads to a hormonal disorder and ultimately to a caloric excess, or in other words to a weight increase

More examples:

• is chronic fatigue syndrome caused by a lack of energy? Is that the cause?
• was our team’s defeat caused by having less points than the rival at the end of the game? Was that the cause?
• did Federer lose his match because he lost the last point? Was that the cause?
• is children growth caused by a caloric excess? Is that the cause?
• did you arrive late tonight because you arrived later than expected? Was that the cause?

Reading further:

• Revisit the causality of obesity
• Why We Get Fat: Adiposity 101 and the Alternative Hypothesis of Obesity