The Volumetrics weight control plan was developed by Barbara Rolls, Ph.D., a veteran nutrition researcher who currently holds the endowed Guthrie Chair of Nutrition at Pennsylvania State University. She has focused on the study of hunger and obesity for more than 20 years and used the science of satiety, or the feeling of fullness at the end of a meal, to help her readers stop dieting and feel full by consuming fewer calories.
Dr. Rolls, along with Robert A. Barnett, write in their book "The Volumetrics Weight-Control Plan," that the basic concept of Volumetrics is to eat a satisfying volume of food while controlling calories and meeting nutritional requirements. It is a lifestyle plan designed to go beyond short-term weight loss and into long-term weight management. According to the authors, if you follow the plan according to the suggestions given, your plate will be full of nutritious food at every meal. Even the energy-dense or "forbidden" foods, such as candy and chocolate, still have a place in the diet, but you need to consider the calories and plan for them. Dr. Rolls and Barnett suggest you keep weight-loss goals reasonable rather than expecting too much and then feeling like a failure. The idea is that slow and steady wins the race and that if weight is lost too quickly, it will creep back on.
As explained in "The Volumetrics Weight-Control Plan," the five major components are fat, carbohydrates, protein, alcohol and water. Whether it is butter, oil, or the visible marbling of a steak, fats are the most energy-dense of all food components and it is suggested that a moderately low-fat diet of 20 to 30 percent of calories be maintained. By decreasing the fat content of your diet, it will lower energy-density and allow you to eat more satisfying portions of lower calorie foods. Most of the calories in this diet plan, or about 55 percent, are to come from complex carbohydrates, which are found in plant foods such as grains, potatoes, beans and vegetables. Although they contain sugar, fruits are rich in water, fiber, vitamins and minerals and you should include them. Protein foods are important because they prolong satiety and help you feel less hungry while greatly restricting calories. Moderate potions of lean, protein-rich beef, chicken, seafood, low-fat dairy foods and legumes are to comprise about 10 to 15 percent of the diet. Although alcohol is energy-dense, moderate drinking, which is considered to be one drink daily for a woman and two for a man, is acceptable, but you need to take the calories into consideration. Drinking sufficient water is an important part of the Volumetrics plan as it helps move food through the digestive tract, carry nutrients from the blood to the cells, eliminate waste products, lubricates joints and is critical for maintaining body temperature.
The main criteria in making food choices is the energy density of foods and the lowest energy-dense foods are usually the lowest in calories. This includes most fruits and vegetables, skim milk products and broth-based soups. According to Dr. Rolls and Barnett, energy density is not the only guide to choosing foods as the best nutritional guidance should come from the U.S. Department of Agriculture's Food Guide Pyramid, which suggests the base of the diet should be breads, cereals, rice and pasta. The next tier, which is composed of vegetable and fruits, should be eaten in abundance. The following tier consists of dairy foods and protein-rich foods that should be consumed in smaller portions while the smallest tier is composed of fats, oils and sweets, which you should eat sparingly.
The Volumetrics plan provides a base of 1,600 calories per day with suggestions for ways to provide calorie levels that are higher or lower. You are encouraged to estimate your individual calorie needs based on height and activity level and then reduce intake by about 500 calories per day to lead to weight loss of about 1 lb. per week. You should eat everything at each meal so that you feel full and, if desired, include more vegetables, except for starchy ones like potatoes and corn, as they will only slightly increase the calorie intake.
In stating the importance of exercise in their book, "The Volumetrics Weight-Control Plan," Dr. Rolls and Barnett share that becoming more physically active will increase metabolism, help you burn more calories and will assist in staying committed to a healthier way of eating. According to the authors, you don't have to become an athlete to keep the weight off, but you must move as frequently as possible. Increasing "lifestyle activity" in ways that do not seem like exercise, such as turning off the television and walking more, can be an effective weight-loss tool.