Even though you hear a lot of bad things about fat, it is a necessary nutrient when consumed in the right amounts. Fat helps supply energy for aerobic exercise in the form of fatty acids and may help you lose weight. Fat also protects your organs by insulating them against the cold, helps to make cell walls permeable so that necessary nutrients can flow between the cells and the blood, and serves as a building block for hormones. It is important to keep fats in your diet but to eat the right types in limited quantities.
Just because something is listed as having 0 percent trans fat, doesn’t necessarily mean that it is completely trans-fat free. In terms of labeling, it’s important to note that trans fat may not be listed. If the words partially hydrogenated, margarine, or shortening appear in the ingredients list, the product contains some artificial trans fat. Ingredients are listed in decreasing amounts, so if the hydrogenated fat or shortening appears toward the beginning of the list, each serving probably has close to 0.5 gram of trans fat. If it appears toward the end of the list, there are probably close to 0 or 0.1 gram of trans fat per serving. If you purchase and eat processed foods, look for the phrase no trans fat. In this labeling, zero doesn’t mean zero, but no means what it says.
Labels sometimes us the terms partially hydrogenated and hydrogenated interchangeably, so avoid products that use either phrase. The words esterification or esterified are also red flags indicating fats that have been manipulated with chemicals.
Your body is working all the time: pumping blood, processing food, even thinking. The body’s unit of measurement for the amount of work it’s doing is the calorie. When you sit and think, you burn about a calorie per minute. When you take a walk, your body might burn from 3 to 6 calories a minute. For every liter of oxygen (per kilogram of body weight) you process during aerobic exercise, the body burns 5 calories. The more energy you use, the more oxygen you process, and the more calories you burn. Ideally, you should burn 300 calories or more per exercise session.
Your body’s calorie usage during any given activity is determined by your weight, your fitness level, and the amount of work you’re doing. Because of the difference in the muscle/fat ratio of their bodies, as well as their fitness levels, a slight, older woman burns fewer calories taking a walk than a young, muscular man.
Regular physical activity helps keep your muscles toned and strong, maintains bone strength and density, and improves and maintains your heart and lung functions. Exercise also builds stamina, improves flexibility, boosts your immune system, makes sex more fun, reduces your risk of cancer, improves your reflexes, lowers stress, and benefits your overall physical and mental health. But even more important, exercise is a great way to ensure your metabolism functions at maximum capacity.
Exercise can be divided into three specific types: general activity, activities to build stamina, and exercises to increase strength and flexibility. If you want to age well, maximize your metabolism, and add many more active and vibrant years to your life, it’s important to incorporate all three aspects of exercise into your lifestyle. It’s also highly important that you begin slowly, set realistic goals, and see a doctor before you begin any new regimen. Don’t over do it, but remember that the harder you’re working, the harder your metabolism is working, too!
Most of the food you eat is digested and then converted into energy through the process of metabolism. This process, experts day, involves a complex network of hormones and enzymes that not only convert food into fuel but also affect how efficiently you burn that fuel. Within it, there are two contrary, yet complementary, simultaneous processes:
- Catabolism. This is the breaking-down process. Your body creates energy by deconstructing digested food or stored fat into simpler substances so it can use them in other ways. Fats are broken down into glucose, galactose, and fructose and used as the primary energy that fuels the body during the day. Proteins are broken down into amino acids, which the body uses to rebuild or repair tissues.
- Anabolism. This is the building-up process. Your body uses energy from glucose and other molecules to build cells, move muscles, and carry out other vital functions. For instance, the glucose from carbohydrates can be used to make glycogen chains, the glycerol and fatty acids from fats can form triglycerides, and the amino acids from proteins are used to remake other proteins.
The term metabolism refers to the way your body processes and utilizes the food you eat, not to the amount of time required to do so. In other words, it’s not how fast you metabolize food, but how efficiently you convert food into energy. The process of metabolism consists of the following three components:
- Basal metabolism: 60 to 65 percent of the calories you eat daily provide the basic energy you need to stay alive – breathing, circulating blood, organ functioning, adjusting hormonal levels, growing and repairing cells, and so on. Even if you lie on your sofa all day, your body will burn these calories to support basic body functions. How many and how efficiently you burn calories to meet these needs is called your basal metabolic rate (BMR).
- Physical activity: 25 percent of your calories support movement and physical activity. The frequency and intensity of physical activity can positively or negatively affect this aspect.
- Food processing: 10 percent of calories are expended ingesting, digesting, absorbing, transporting, and storing your caloric intake. This is called the thermic effect, or the energy your body expends processing the food you eat. For example, if you eat 2,000 calories a day, approximately 10 percent, or 200 calories, will be used eating and digesting your food.