I recently went on a high protein diet and lost 17 lbs over a period of 3.5 months, from 132 lbs to 115 lbs. I'm 5'3" tall. During that time, my diet comprised mainly of egg whites, lean red and white meats, fish, tofu, plenty of low-dat yogurt, 2 tbsps of oat bran per day, and lettuce and greens on alternate days. Since a month ago, I have been eating normal again and have introduced fruits and carbohydrates (part complex and part simple) back to my diet, but my weight is still dropping, which gets me worried, because "Losing weight without intending to" is a symptom of cancer. My mother lost weight before she was diagnosed with cancer. I've read a lot about how eating red meats and diary are bad for the health and might cause cancer (the casein in the diary and the increase of acidity brought about by the high-protein foods). Other than losing a further 2.5 lbs last week despite eating lots of foods, I feel otherwise healthy. Do I have a cause to be worried?