Are certain carbs derailing your diet? Join this Web chat to find out

Why are so many people obese or overweight? It’s because of our love affair with sugar and starchy foods, says Gary Taubes, author of “Why We Get Fat: And What to Do About It.” Taubes says that the key to weight loss isn’t calories in and calories out nor obsessing about fat but in cutting back on stuff like potatoes and sugar (in all its forms) and eating more protein and even fat. Join a live Web chat with Taubes at 11 a.m. Pacific Time (1 p.m. Central, 2 p.m. Eastern) on Monday, June 6, and find out how you may be sabotaging your weight-loss goals.

We asked Taubes, a contributing correspondent for the journal Science, why people don’t think more critically about their diets, and why so many people fall for the latest diet fad.

“People tend to jump on the latest fad diets because they’re desperate,” he said. “The advice they get from their doctors and health agencies and, yes, health journalists -- eat less, exercise more -- doesn’t help them, at least certainly not in the long term. When the conventional wisdom is wrong, as it is in this case, it leaves the door open to all manner of fads and quackery.”

Even when we stop and think critically about weight loss, we still don’t think about it straight, Taubes says. “Most people believe that thinking critically on this issue means understanding that the calories we consume and expend determine how fat we’ll be -- and therefore that any diet promising weight loss without sacrifice is a diet that somehow violates the laws of thermodynamics. The catch is that this calories-in-calories-out/thermodynamics notion happens to be the precise idea that’s misconceived.

“If the obesity research community, nutritionists and public health authorities, and the journalists covering this field, understood why we really get fat and could communicate that correctly to the people who depend on them to get things right, a lot of these problems would go away. We’d all know why we get fat and what to do about it -- and we’d do it.”

Do you have a question for Gary Taubes? Email jeannine.stein@latimes.com and join the chat on Monday to see the answer.