How to gain weight according to the Lipophilia Hypothesis -- it has nothing to do with "overeating" or lack of physical activity
The Lipophilia Hypothesis tells us that, contrary to what we've been told, overeating and inactivity are actually consequences of weight gain, not causes of it. Again, we refer back to Gary Taubes to help us wrap our heads around why and how this could be. On pages 294-295 of his book, Good Calories, Bad Calories, Taubes explains that, when we store calories in our bodies, the law of energy conservation requires that we must either consume additional calories to compensate or conserve calories metabolically. Thus, when metabolic or hormonal problems lead us to store calories as fat, this primary defect drives us to eat more and/or burn off fewer calories. Hunger does not cause us to get fat; hunger is an effect of gaining fat in the fat tissue. Likewise, indolence does not cause us to get fat either; a slowed metabolism, too, is an effect of the primary insult to the fat tissue.
Taubes goes on to quote an endocrinologist named Hugo Rony, who was quite influential in the mid-1900s. Rony explained that we can (theoretically) fatten people articially by force-feeding and/or force-resting them (much as we fatten geese for fois gras). But in general, obesity happens spontaneously. There is a problem in the body that causes it to store calories as fat, and this engorged fat tissue then seeks to preserve itself by driving what is known as a positive caloric balance. A person gaining weight will ultimately consume excess calories, in other words; but the consumption of those excess calories -- the hunger, the inactivity, etc -- results from what is happening in the fat tissue itself.
There is lots of support for this prediction, but we'll get to "testing" it later when we look at the evidence in detail.
Well, let's start with a taste. Check out this quote about how to gain weight pulled from the April 14th, 2008 proceedings of the National Academy of Sciences:
"A new study done by researchers at the University of Texas Southwestern found weight gain is merely an early symptom of premetabolic syndrome, rather than a direct cause. Excess fat is usually stored in fat cells, causing a person to gain weight. The study emphasizes it's not the growing fat cells that increases a person's risk of metabolic syndrome; it's the actual excess fat itself going into those cells."
This totally supports what Lipophilia theory predicts.
To sum up: the alternative explanation for how to gain weight has nothing to do with excess calories, gluttony, or sloth; it has to do with metabolic and hormonal factors.