For years we've been told that, thanks to their high saturated fat content, the foods for which evolution has adapted us - grass-fed meat, grass-fed dairy products, eggs from hens running on pasture - are unhealthy. In their place we eat processed factory foods - and we've witnessed a growing epidemic of disease, from type-2 diabetes to heart disease and cancer.

It's now clear that the 'food revolution' was flawed. Saturated fat is not the cause of heart disease or diabetes. Far more likely causes are sugar and refined carbohydrates, low-fat spreads and vegetable oils. The really healthy foods turn out to be the ones our grandparents knew to be the best.

There's a simple remedy. We can make sure that the meat, dairy foods and eggs we buy come from animals grazing on or running in pasture. This will also put life back into our soils and wildlife back into our fields and hedgerows.

This book is an urgent manifesto for grass-fed foods - for your health and for the planet.