How To Eat Well When You’re Fatigued

Fatigue is more than just "being tired." Fatigue is a persistent lack of energy — a kind of weakness or inertia that you feel throughout your body.

Fatigue is the most common side effect of cancer treatment. Some doctors estimate that 9 out of 10 people experience some cancer fatigue.

Complex and varied factors cause fatigue, even after breast cancer treatment is completed. Treatment side effects like pain, hot flashes, stress and anxiety, and depression may all contribute to fatigue. 

What you eat can also affect your fatigue. For example, eating less than usual and not getting enough of the nutrients you need because of treatment side effects — like nausea or diarrhea — can cause fatigue. You may also be dehydrated because you've been vomiting or have had diarrhea after treatment — or maybe you're just too tired to keep drinking liquids. This can lead to an imbalance in electrolytes — essential minerals like sodium, potassium, and calcium — and can make you feel weak.

If you're fighting fatigue, it's important to make sure you're getting enough nutrients, especially protein, as well as total calories. These amounts will be different for different people. Together, you and your doctor or your registered dietitian can come up with a healthy eating plan that works for you.

During treatment, your body also needs enough vitamins and minerals, which are called micronutrients. Getting these nutrients from foods rather than from supplements is best. But if you aren't eating very much because of treatment side effects, ask your doctor about taking a multivitamin.

How to eat when you're fatigued:

  • Try meal planning and cooking in bulk. When you have the energy to cook, make a large batch of something nutritious that you enjoy and freeze it in single-serving containers. Then, when you're too fatigued to cook, you can quickly heat one container and eat. If your friends or family offer to cook for you, ask them to do the same.

  • Eat larger portions when you're feeling good. Try to eat your biggest meal when you have the most energy and the biggest appetite. If you get tired by the end of the day, eat more at breakfast and lunch.

  • Eat several nutritious snacks during the day to boost your calorie and protein intake. String cheese, dried fruit, yogurt, baby carrots, nuts, trail mix, and cut-up vegetables are easy to keep handy. This way, you don't have to face eating a big meal.

  • Try a prepackaged liquid nutritional supplement or an energy bar rather than skipping a meal entirely. Every little bit helps.

How to get more protein in your diet

In the body, proteins build and repair cells, boost the immune system, and stabilize blood sugars, which can prevent energy crashes. “We know that cancer treatment increases the amount of nutrients our bodies need, especially protein,” says Hillary Sachs, MS, RD, CSO, CDN.

Good sources of protein include fish, poultry, dairy products, nuts, dried beans, peas and lentils, soy, and lean meat. To get more protein each day, try some of these tips:

  • Aim to get a 3-ounce portion of protein foods at each meal (e.g., fish, poultry, tofu, tempeh, or edamame).

  • Eat hard-boiled eggs. Keep them in the refrigerator as a snack. Add chopped hard-boiled eggs to salads and sandwiches. 

  • Add nuts and seeds to baked goods, yogurt, smoothies, or cereal.

  • Add several kinds of beans to pasta sauces or chili.

  • Add nut butter to sandwiches, toast, crackers, muffins, fruit slices, oatmeal, or smoothies.

  • Use Greek yogurt instead of regular yogurt. It tastes great in sauces and dips, or as a substitute for sour cream.