Jackie is a 21-year-old health-conscious individual majoring in business. she recently learned that a diet high in saturated fat can contribute to high blood cholesterol and that exercise is beneficial for the heart. jackie now takes a brisk 30-minute walk each morning before going to class, and she has started to cut as much fat out of her diet as she can, replacing it mostly with carbohydrates. a typical day for jackie now begins with a 2-cup bowl of fruity pebbles with 1 cup of skim milk and ½ cup of apple juice. for lunch, she might pack a turkey sandwich on white bread with lettuce, tomato, and mustard; a 1-ounce package of fat-free pretzels; and five reduced-fat vanilla wafers. dinner could be a 2-cup portion of pasta with some olive oil and garlic mixed in, and a small iceberg lettuce salad with lemon juice squeezed over it. her snacks are usually baked chips, low-fat cookies, fat-free frozen yogurt, or fat-free pretzels. she drinks five diet soft drinks throughout the day as her main beverage. is it necessary for jackie to drastically lower her fat intake to achieve heart health?