The three macronutrients the human body requires to remain healthy are fats, carbohydrates and proteins. A chicken and avocado sandwich provides all macronutrients and is a good source of dietary fiber.

When choosing which type of bread to eat, you should consider the fiber content if you are trying to lose weight. High-fiber breads support weight loss as the fiber helps to keep your blood sugar steady, which reduces the likelihood of craving sugary foods. High-fiber foods also promote a feeling of satiety. A 1 oz. slice of white bread provides 75 calories and about 0.7 g of fiber. A slice of mixed grain or pumpernickel bread has 71 calories and 1.8 g of dietary fiber.

Avocados are rich source of monounsaturated fats. According to Liz Vaccariello, author of "Flat belly Diet," eating a small amount of MUFAs with each meal will help reduce abdominal fat. An ounce of avocado flesh provides 45 calories. One-half of an avocado fruit has around 160 calories, 15 g of fat and approximately 6 g of dietary fiber, which is around 20 percent of the recommended daily intake for adults.

A one ounce slice of deli-style chicken roll has around 44 calories. An ounce of chicken breast strips contains 34 calories.

If you prepare your sandwich using 3 oz. of deli chicken, half an avocado and two 1-oz. slices of white bread, it will contain around 445 calories. A sandwich made with two thin slices of rye bread, a quarter-cup of avocado and 2 oz. of chicken breast would provide around 230 calories.