One of the most common questions we hear in the pharmacy, especially as we start a new year, relates to what we might suggest to reduce someone’s appetite so they might lose weight. Some of those who ask don’t believe my simple answer- that there is nothing appropriate for that purpose. I guess they want too much to find that magic pill, promised by all the marvelous marketing, which will relieve us of responsibility from our own inappropriate lifestyles. I try to point out that we don’t overeat from hunger but from habit and that the agents that suppress appetite all have significant negative effects on our long term health. At this point our questioners divide; some leave to seek a different answer elsewhere (after all, the people on TV said it worked for them!) and others move on to the more appropriate question: what should we do to begin a healthy weight loss program? And there begins this discussion…
Let’s look first at some general issues related to metabolic regulation. Basically we seek caloric balance, matching total calories consumed to our energy needs. We need to realize, however, that even though from a physics standpoint a calorie is a calorie (a unit of energy), when it comes to our metabolism every calorie is not alike; that calorie sources, timing of consumption, digestive activity, and endocrine responses all may alter whether a calorie is spent or stored. Caloric restriction alone has value, yet the more we restrict intake the more our body slows metabolic function in order to conserve energy reserves.
Two concepts that help us understand caloric utilization are glycemic index and glycemic load. Glycemic index is a relative value showing how quickly a food converts to blood glucose compared to table sugar. High glycemic foods may raise glucose levels so rapidly that we store (as fat) the excess beyond our ability to burn; low glycemic foods spread the same calories over a greater time, allowing us to use the glucose as fuel for energy now rather than storing for lean times that may never come. Glycemic load compares the amount of carbohydrate in a food to the glycemic index of that food to show the relative insulin release required for processing. Foods with higher glycemic load are culprits in developing insulin resistance, an impaired pathway leading to obesity, hypertension, elevated cholesterol, increased cardiac risk, and Type II diabetes.
Meal spacing, or how we distribute calories consumed through the day, directly affects energy and weight. Animal studies show that one large meal a day leads to weight gain and loss of energy, the same calories divided in three meals leads to normal weight and activity, and that further dividing in five meals leads to increased lifespan. Increasing our intake of high fiber foods such as non-starchy vegetables and whole fruits increases our satiety, or feeling of fullness, and leads to fewer calories consumed. Drinking more water improves intracellular energy processes and speeds detoxification. Sweetened drinks, including juices, do provide fluids but are significant sources of excessive sugars, adding to weight gain and slowing our immune responses.
Improving our digestive capacity can be central to any program of weight loss. Stress, whether chronic or acute, inhibits secretory activity, reducing our ability to digest and absorb the micronutrients necessary for maintaining healthy metabolic function. Digestive processes differ for different types of food; some foods require acid for digestion and others require an alkaline environment. This difference leads to the concept of food combining to enhance digestion. This concept allows foods with similar digestive pathways to be combined but foods requiring opposing digestive secretion to be eaten at separate times. Generally this would indicate that protein and fats, protein and vegetables, or vegetables and starches could be combined but protein and starches should not be eaten in the same meal, and that fruits should be eaten alone.
So far we’ve discussed issues of caloric intake- let’s look briefly at the importance of physical activity. I recently came across published data estimating that in my lifetime (fifty years) the physical work required for meeting the activities of daily living had decreased almost 40%. In the same time our total calories consumed have decreased slightly but our sugars consumed (and processed food in general) has skyrocketed. We must remember that muscle is our primary tissue to burn calories. Exercise increases calories spent (not stored), increases muscle mass (more tissue to burn calories), and increases our response to insulin, allowing us to burn calories more efficiently rather than storing more body fat. Exercise may be aerobic, intended to burn calories, or anabolic, intended to build muscle, but for most of us must be increased if we are to see significant change in our health and weight.
We will start next the discussion by looking at endocrine regulation of metabolic function, including overviews of thyroid, adrenal, ovarian, and testicular hormones, and take a special look at insulin and glucagon, hormones produced in pancreatic islet cells. Our discussion will continue as we explore the use of nutritional agents to improve metabolic function and speed weight loss and we will conclude with a discussion of specific dietary patterns demonstrated to help restore optimum health. Remember, we don’t usually get out of shape overnight and it will also take time for healthy changes to accumulate. Start examining these basic issues and we’ll be ready for our next steps in the next article.