The main message of the book is this: Eat food. Not too much. Mostly plants.
Basically the book highlights how those of us who follow 'the western diet' have lost our way; how much of what we eat isn't strictly 'food' (rather 'food-like substances'), courtesy of nutrient-poor industrially farmed foods and corner-cutting due to food processing; how the age of 'nutritionism' (the obsession with food constituents and their purported benefits for our health) is actually making us less healthy.
The first section of the book explores the rise of nutritionism, and presents findings of various studies and experiments that ultimately suggest that 'western eaters' today are significantly less healthy -- ie more prone to heart disease, obesity, cancer and diabetes -- than our predecessors. So what has gone wrong? Pollan's argument (backed by the opinions of numerous experts) is that our mistake (or, rather, that of the industrial food companies) has been breaking down food into 'nutrients' and treating them in isolation. The finely tuned human body actually needs saturated fats and all the other food consituents you can think of. We don't have nearly enough understanding of how they behave synergistically to meddle successfully.
The second section of the book outlines the key areas in which our diets have changed:
- From whole foods to refined - we get fewer nutrients, delivered too efficiently (especially glucose and fructose) and consequently absorbed too quickly
- From complexity to simplicity - a trend towards simplification (of nutrients) at all stages of the food chain, meaning we don't get enough nutrient diversity.
- From quality to quantity - leading to humans becoming over-fed and under-nourished
- From leaves to seeds - reflected by the dominance of grains (especially processed corn, soybeans, rice and wheat) which leads to an imbalance of omega 3 vs 6 among other issues
- From food culture to food science - the role of food and eating has changed from a cultural perspective
The final section of the book outlines some practical recommendations as to how we can change our eating to overcome the curse of the western diet. Basically this involves avoiding processed foods of any kind, eating organic where possible, shunning foods that make health claims on the packaging. He recommends we 'eat mostly plants, especially leaves', think about where our food comes from, and cook form scratch wherever possible. A glass of wine with dinner is considered good (yay). The book also outlines some strategies to help us eat less overall.
All of this has me in a bit of a spin, I confess. In the past few years I've endeavoured to improve my diet, but I have to admit to a reliance on processed foods. Cooking is not really my thing, and so if I can cut corners, I will. As a result, the strategies proposed by In defence of food fly counter to many of my eating habits, so for me to implement will involve a major shift in thinking. Step 1: Get rid of the margerine.