Book review: The Diet Myth

Book cover for The Diet Myth by Tim Spector

One of my primary reading genres is books about health and nutrition. I feel it’s vitally important that we’re aware of what we’re feeding our bodies. I typically make it a point to read at least one book from this group every year, although I wouldn’t mind reading more. Unfortunately, I’d gotten away from reading in this area over the last year or two with the last good book I read about nutrition being The Complete Guide to Fasting by Dr. Jason Fung back in in 2019 (which I would highly recommend, by the way).

One of the challenges with reading health and nutrition books is identifying books based on solid science. There are so many books on the subject that it can be hard to separate the wheat from the chaff. Depending on the quality of the book, suggestions can be life changing for the better, or, if not researched properly and supported by quality data, they can have negative effects on one’s health, potentially even hazardous outcomes in the extreme.

Fortunately, one of my favorite blogs, A Learning a Day, made a strong recommendation for a nutrition book, The Diet Myth by Tim Spector. Given the good experiences I’ve had with previous recommendations from the blog, I added it to my (lengthy) reading list and finally got around to reading it.

Before I even started to read the book, there were a couple of things I liked about it. First was the author’s background. Tim Spector is a Professor of Genetic Epidemiology at Kings College, London and is well respected in his field. He has been researching the effects of food and diet on our health for the majority of his research career. In other words, the majority of Spector’s findings are based on data from scientific studies and not casual observation, and Spector is quick to identify any of his findings that are based on the latter rather than the former.

The second piece I liked is that Spector does not provide a blueprint for the perfect diet. He does not espouse a one-size-fits-all approach to maintaining optimal health. He recognizes that while there are some common themes, everyone is different. We are influenced by our genes, our environment, and our experiences, all of which have a significant influence on our body’s health and function. What might work well for one group of people may not work at all for another group. For example, he uses his studies of sets of twins, both identical and fraternal, to show how even those with the same, or close to the same, sets of genes can react differently to the same foods. Then he shows how the change grows when compared across different sets of twins. While not a completely controlled study, it’s about as close as you can get to identifying the effects of genetics on diet.

At the end of the day, there were five primary things I took from Spector’s work:

  1. A one-size fits all approach does not work for diet and nutrition because we are all different at some level.
  2. Genetics, which we have no control over, plays an important role in our propensity for obesity and disease. The more we understand about the role of genetics, the more we will be able to tailor and optimize diets by individual.
  3. We are finding that our microbiome, aka gut-health, which is poorly understood and an evolving field of study, plays a critical role in our health. Fortunately, our microbiome can be influenced through our diet choices. Spector strongly suggests that as we understand more about how the microbiome works, diets will be prescribed by individual based on the make-up of the bacteria in their gut.
  4. Food diversity and moderation is key, and processed, refined, and high sugar foods should be avoided at all costs.
  5. Fermented foods (e.g. yogurts, keifer, sauerkraut, kimchi, kombucha, soft cheeses) are good for us as they feed and encourage the growth of the good players in our gut.

I liked The Diet Myth, but I found it a hard book to rate. For me, it meandered in places with anecdotes and stories that didn’t necessarily fit the flow of the book. Some of the information was based on Spector’s own personal experiences and observations, which wasn’t particularly useful although he does clearly indicate where this is the case.

That said, I would still consider the book a Must Read given the importance of the information it contains, with one caveat. If you’re going to read The Diet Myth, I’d also recommend reading Grain Brain, Wheat Belly, and The Complete Guide to Fasting (linked above). I’ve found that reading numerous, quality books on nutrition and health has helped me, and will help you, identify common nutrition themes. These are the things everyone appears to agree upon when it comes to diet – food diversity, avoiding processed foods, limiting sugar intake, eating fresh fruits and vegetables, and moderation, especially when it comes to meats. By reading widely, you’ll be better informed and make better decisions regarding the affects of diet and nutrition on your health.

Thanks Tim for sharing your research through The Diet Myth. It helped me to fill in quite a few holes I had in my understanding of diet and nutrition. And thanks to Rohan for sharing the recommendation on his A Learning a Day blog.