Deep Nutrition

Deep Nutrition argues that human health, including the shape of the face and skeleton, reflects the quality of the diet eaten by previous generations, and that industrial food has broken a nutritional inheritance that traditional cuisines preserved. Catherine Shanahan's thesis is that returning to ancestral food patterns supports health in ways that nutrient-by-nutrient thinking misses.

The practical framework is what she calls the Four Pillars, found across traditional cuisines: meat cooked on the bone, organ meats and other whole-animal foods, fermented and sprouted foods, and fresh raw plant and animal foods. Against these she sets two modern additions she treats as primary drivers of disease, refined sugar and industrial vegetable oils. Her argument on seed oils is that polyunsaturated fats oxidise readily under heat and processing, generating reactive breakdown products that damage cell membranes and blood vessels.

It is for readers drawn to a whole-foods, traditional-cuisine approach and interested in the reasoning behind it.

On the evidence, the two halves of the book differ. The general advice, more whole foods, fewer refined carbohydrates and less ultra-processed food, is consistent with what the nutrition literature supports. The specific claims are shakier. The epigenetic argument that dietary history shapes facial development is built largely on Weston Price's early twentieth-century photographs and observations, which are anecdotal and confounded by everything else that changed in those communities. Lipid oxidation products are a legitimate area of research, but the conclusion that seed oils are a leading cause of chronic disease goes well beyond it, and large observational and trial data generally associate replacing saturated with polyunsaturated fat with better cardiovascular outcomes. Read the food philosophy with interest and the mechanistic certainty with caution.