The New York Times Ask Well column has some bad news for anyone who is getting older, meaning everyone. Yes, it does get harder to lose weight the older we get. Health columnist Karen Weintraub tell us why: muscles burn far more calories than fat does, and muscles, as we age, tend to go away. Fat doesn’t. Wait, it gets worse. Weintraub quotes Medha Munshi, a geriatrician and endocrinologist at Beth Israel Deaconess Medical Center in Boston, who adds that declining levels of estrogen and testosterone compound the effect. What to do? Dr. Munshi recommends weight training, and eating well, meaning protein, but not calories.