Doctor says my thyroid hormones are good (I'm on 125mcg synthroid), my glucose tests came back normal, so why can't I gain weight? I've been consuming more calories and eating healthy, so what gives? I'm at 98 pounds right now(5'3 height) fluctuating up to 100.4 at night for the last 3 months, my work is physically demanding, I lift a lot about 3-4 days a week and I don't know I'd like to gain 10 lbs but nothing I've tried worked (including upping protein, fat and carb consumption), is there anything I should be worried about?