I know that I really shouldn’t comment on this research without reading the actual journal article but that hasn’t been published yet and I can’t resist jumping into the fray. Is there a fray? Not really. I just keep seeing people retweeting this and everyone seems all excited about the possibility of these individualized and I need to put a little rain on the parade.
The article starts off sounding great. Who doesn’t want a bespoke diet? Considering the number of people who have asked me as a dietitian to “just tell me what to eat” I think that most people want someone to hand them a nice little meal plan. Of course, most meal plans would be “bespoke” in a sense as any professional worth their credentials is going to tailor the menu to the client. But, I’m not here to quibble about what exactly makes a meal plan bespoke.
So, apparently the researchers looked at how different people react (in terms of blood sugar) to the consumption of different foods. They found a wide range of responses and linked those responses to the types of gut microbes residing in the participants digestive tracts. Then in another study (of only 20 participants) each participants was given a unique diet to control blood sugar and one that was designed to increase blood sugar. Unfortunately, the diets aren’t described in the article so it’s hard to say how much they differed for each participant. There’s also no explanation as to how this ties in to the earlier research looking at the microbiome. In a shocking turn of events, on the diets designed to control blood sugar some (again the article doesn’t indicate how many) participants blood sugar levels returned to normal. On the “bad” diets they had blood sugar spikes that “would be described as glucose intolerant” according to one of the researchers. Essentially, they exhibited diabetes or similar conditions.
The article then goes on to say that this research somehow shows that calories aren’t the only player when it comes to weight loss. What? I thought the research was looking at blood glucose levels. There was no mention of weight change in participants. While I certainly agree that there are many other factors at play, in addition to calorie consumption when it comes to weight management, I fail to see how this research examined this issue at all.
What makes me a little more leery about this study is that the researcher says it’s surprising that ice cream (for example) doesn’t cause huge blood sugar spikes, and that buttered bread has less impact on blood glucose than unbuttered bread. Have these people not heard of glycemic load before? Of course blood glucose responses are going to be mitigated when high carbohydrate foods are consumed with fat or protein. That’s why it’s important to look at how people are consuming foods rather than examining the effect of specific foods in isolation.
I’m trying to withhold full judgement until the research is published. I think that the human microbiome is a fascinating emerging area of research. However, on the basis of this article all I’m envisioning are more scam diet books urging people to eat for their microbes.