Eating is tremendously affected by most types of chemotherapy. Listed below are several common side effects of treatment that often prevent good eating. Other side effects that affect eating—nausea, vomiting, diarrhea, constipation, and mouth and throat sores— are covered in detail in Chapter 12, Common Side Effects of Chemotherapy. In addition, cranial radiation can change the way food tastes, making previously loved foods bland and undesirable.

Loss of appetite

Loss of appetite is one of the most common problems associated with cancer treatment. Children suffering from nausea and vomiting, diarrhea or constipation, altered sense of smell and taste, mouth sores, and other unpleasant side effects understandably do not feel hungry. Loss of appetite is most pronounced during the intensive periods of treatment. If your child loses more than 10 to 15 percent of her body weight, she may need to be fed intravenously or by nasogastric tube. Sometimes this can be avoided if parents learn how to increase calories in small amounts of food.

In addition to simple loss of appetite, your child may experience a side effect of chemotherapy called early filling. This means the child has a sense of being full after only a few bites of food. If your child is suffering from early filling and only eats when hungry, she may begin losing weight and become malnourished. This chapter provides dozens of creative ways to encourage your child to eat more.

Increased appetite and weight gain

When children are given high doses of steroids such as prednisone or dexamethasone, they develop voracious appetites. They are hungry all the time, develop food obsessions, and frequently wake parents up during the night begging for another meal.

Most parents become very concerned if their child consumes huge quantities of food and gains weight. A moon face with chubby cheeks and a rotund belly are classic features of a child on high-dose steroids. Much of the extra weight is fluid, which steroids cause the body to retain. There are two important points for parents to remember about treatment with steroids. First, when the steroids stop, the extra fluid is excreted and weight drops. Second, the child’s appetite may go from voracious to poor after the steroids stop, so it is unwise to limit food when your child is taking steroids. Instead, try to make the most of this brief time of good appetite to encourage consumption of a variety of nutritious foods. A well-balanced diet now will help your child withstand the rigors of the treatments ahead.

If you are concerned about the weight gain, consult your child’s oncologist. If the fluid retention is extreme, the doctor may have you restrict your child’s salt intake; in some cases, children are given drugs called diuretics to rid the body of excess fluid.

Lactose intolerance

Lactose intolerance is when the body can’t absorb the sugar (lactose) contained in milk and other dairy products. Both antibiotics and chemotherapy can cause lactose intolerance in some children. The part of children’s intestines that breaks down lactose stops functioning properly, resulting in gas, abdominal pain, bloating, cramping, and diarrhea. If your child develops lactose intolerance, it is important to talk to a nutritionist to learn about low-lactose diets and alternate sources of protein. The following are suggestions for parents of lactose-intolerant children:

• Add special enzyme tablets or drops to dairy products to make them more digestible for children with lactose intolerance. Some of these products are over-the-counter additives, but others require a prescription. Discuss these additives with the oncologist before giving them to your child.
• Children who cannot tolerate the lactose in cow’s milk often can manage acidophilus milk, soy milk, rice milk, almond milk, or lactose-free milk. These are easier to digest and come in a variety of flavors.
• Always be sure dairy products are pasteurized, not raw.
• Remember that milk is a common ingredient in other foods, such as bread, candy, processed meats, and salad dressings. Read ingredient lists carefully.
• If your child can’t tolerate any dairy products, add calcium to his diet by serving canned salmon, sardines, spinach and other green leafy vegetables, or calcium-fortified fruit juices. Consult your child’s oncologist and nutritionist about calcium supplements. Many children like the taste of a chewy calcium supplement called Viactiv®, which is available at most drug stores.

Altered taste and smell

One common reason children on treatment do not eat is because, for them, food has no taste or tastes bad. If food tastes bland to your child, try serving spicy cuisines, such as Italian, Mexican, or Greek foods.

Chemotherapy often causes foods, particularly red meats, to taste bitter and metallic. If that happens, avoid using metal pots, pans, and utensils, which can magnify the metallic taste. Serve your child’s food with plastic knives, forks, and spoons. You can also replace red meat with tofu, pork, chicken, turkey, eggs, and dairy products.

For some children, taste returns to normal after treatment ends. And for a few children, it takes years before some foods taste pleasant again.