IN SUMMERTIME not only is the living easier, but making changes in our eating habits is easier. Our appetites are lighter, our cravings for heavy and fatty foods are diminished, and the fruits of the season tempt us. As in winter, when we resolve to shed pounds or start jogging for bathing suit season, so in summer we can experiment with lower fat levels in our diet and establish new inclinations before eggnog season returns.

We can also be more flexible about what we consider a meal. Pancakes obviously make a fine breakfast. They can also make a satisfying dinner, and a quick one, too.

This pancake recipe is adapted from one developed at the Pritikin Center to meet its low-fat, low-cholesterol, high-fiber, high-carbohydrate requirements. Thus its flour is whole wheat, its milk low fat and its egg just the whites. The sauce suggested for the pancakes is sweetened by very ripe bananas rather than sugar; season it to your taste with vanilla, nutmeg or a combination of all three.

Since Pritikin recipes contain no salt or oil, all you need to have on the shelf is flour (whole wheat, of course), then you can jog through the express lane for the following ingredients:

EXPRESS LANE LIST: baking powder, buttermilk (fresh or powdered), skim milk, apple juice, eggs, bananas, yogurt, vanilla. PRITIKIN PANCAKES (4 to 6 servings) 1 1/2 cups whole-wheat pastry flour 1 1/2 teaspoons baking powder 2/3 cup buttermilk* 2/3 cup skim milk 1 tablespoon apple juice concentrate, undiluted 2 egg whites

Stir together flour and baking powder in a large bowl. Combine buttermilk with skim milk, apple juice concentrate and egg whites, then lightly stir into flour mixture. Batter will be lumpy; do not overbeat. If batter is too thick, add more milk. Using a large measuring cup to pour batter, form pancakes on a preheated non-stick skillet. Cook until small holes form on the top, then turn pancakes and cook until golden. Keep warm on a heated platter until ready to serve. Serve with banana sauce (recipe below) and fresh fruit.

*If using dried buttermilk powder, add 2 1/2 tablespoons of powder to the dry ingredients and 2/3 cup water to the skim milk, then proceed as directed. BANANA SAUCE (4 to 6 servings) 3 very ripe bananas 1/8 cup yogurt 1/4 teaspoon vanilla or 1 teaspoon cinnamon or 1/8 teaspoon nutmeg, or combination

Combine ingredients in blender or food processor and serve on top of pancakes.