It appears Gary Taubes has completed his series critiquing the food reward hypothesis of obesity (
1). I have to hand it to him, it takes some
cojones to critique an entire field of research, particularly when you have no scientific background in it.
The food reward hypothesis of obesity states that the reward and palatability value of food influence body fatness, and excess reward/palatability can promote body fat accumulation. If we want to test the hypothesis, the most direct way is to find experiments in which 1) the nutritional qualities of the experimental diet groups are kept the same or at least very similar, 2) some aspect of diet reward/palatability differs, and 3) changes in body fat/weight are measured (for example,
2,
3,
4,
5,
6,
7,
8,
9). Taubes repeatedly stated in his series that controlled studies like these have not been conducted, apparently basing this belief on a 22-year-old review paper by Dr. Israel Ramirez and colleagues that does not contain the word 'reward' (
10). Another way to test the hypothesis is to see if people with higher food reward sensitivity (due to genetics or other factors) tend to gain more fat over time (for example,
11,
12,
13,
14,
15,
16). In addition, studies that have examined the effect of palatability/reward on food intake in a controlled manner are relevant (
17,
18,
19,
20,
21,
22), as are studies that have identified some of the mechanisms by which these effects occur (reviewed in
23). Even if not all of the studies are perfect, at some point, one has to acknowledge that there are a lot of mutually buttressing lines of evidence here. It is notable that very few of these studies appeared in Taubes's posts.
Read more »
