Did you know that exercising does not help you lose weight? Or that eating too much does not make you fat? According to the new (2011) book by science journalist Gary Taubes, the failure of modern science and public health to acknowledge the primary reasons we get fat: excess carbohydrate in our diets, is the cause of our worsening obesity epidemic and rising rates of its related illnesses: diabetes, heart disease and cancer.

Low-carb diets, according to Taubes, have been a reliable program for weight reduction for over 100 years, but since the 1960s they have been relegated to the fad-diet dustbin and dismissed as ineffective, dangerous or both. On the other hand, the science that the low-fat, calorie-reduction proponents have relied upon to make their case for the past 40 years is unreliable and inconclusive at best, and misleading at worst.

Obviously, thems are fighting words, and there has been significant backlash against Taubes’ “alternative hypothesis”. (He’s been writing about it since 2002. ) But the tide seems to be slowly turning, as researchers at increasingly respected institutions (like Harvard) are producing results that support what we already, apparently, knew.

If continued mainstream study (which is much of what Taubes is advocating) tips the weight of evidence towards the carbs-are-fattening camp, we could see a dramatic reversal in public health policy. Good science is often slower than public opinion to make up its mind, and once that mind is made up, it is even harder to shift a ‘consensus’. Rigorous examination of the evidence and articulate, even passionate, calls for change are not misplaced in the face of a daunting health ‘epidemic’.

The dust has not yet settled on this debate, and there is much of our understanding that still needs to be developed, but reading “Why We Get Fat” is an important stop on the journey for anyone looking to live a healthier life.