HOW we lose weight (and lower blood pressure) really matters

Last month, the Journal of the American Medical Association published an issue that featured the revelation that gastric bypass (bariatric or stomach stapling) surgery raises the risk of early death “considerably higher than previously suggested.” Those who had their stomachs stapled were promised lower risk of health problems and longer lives because their obesity equated to more adverse health outcomes. Public health campaigns have bombarded us all with the strong message that excess weight is unhealthy. Excess weight is unhealthy. So why didn’t this dramatic surgery that consistently reduces obesity work out as planned? The research addresses the broader question: does everyone who loses weight lower their risks of the adverse outcomes associated with obesity? Or, put another way: does it matter how someone reduces weight or just that they reduce excess weight? But that’s not the question I want to answer. You’ll have to read JAMA for that answer. What I wanted to point out is the strong parallel here with another recommended intervention which, its advocates promise, will reduce health risks, improve health and extend lives. That intervention isn’t bariatric surgery; it’s salt reduction. Consumers are bombarded with public heath messages telling them that cutting back salt will save their lives. Is that true or is it more like stomach stapling? Consider the parallels. A gastric bypass will result in the patient eating less and losing weight. Salt reduction, for a significant minority of the population, will reduce blood pressure. Obesity is strongly correlated with adverse health problems and increased mortality. Elevated blood pressure, likewise, is correlated with increased risk of heart attacks and strokes. The simplistic answers of bariatric surgery or salt reduction rest on the assumption that it makes no difference how a person loses weight or lowers high blood pressure – Just do it! The JAMA papers suggest that this isn’t true for obesity. A dozen papers examining salt intakes and comparing them to health outcomes reach the same conclusion: it matters a great deal how blood pressure is lowered. Salt restricted diets do not reduce adverse health outcomes; in fact, some of the studies show elevated risks, just as the JAMA papers find for stomach stapling. Read more about salt and health on the Salt Institute website.