Activities, calories burned

The problem with all those diets, as is true with any diet, is that for virtually everyone, going on a diet means going off that diet. The only approach that really works is to change one s lifestyle enough to reduce the number of calories taken in as food and to increase the amount of calories burned through physical activity. In other words, you need to go on the No-Fad Diet, as Dr. Robert Eckel called it in his editorial accompanying the article that compared the four diets mentioned above. 

Table 33-8 lists a classification of work by severity. Some work involves higher activity levels than other work. Associated with level of severity is the typical rate of oxygen consumption and calories burned. Units of measure for the rate at which people bum energy are kcal/min or Btu/hr. 

Calculate the total number of calories you bum per day. Use basal metabolism for sleeping hours, and between 90 and 150 Cai/h, depending on your weight and activity level, for your waking hours. If you exercise regularly, include the number of calories burned during your exercise. (Moderate exercise uses about 300-500 Cal/h while strenuous exercise uses 500-700 Cal/h.)... 

The human body is designed to take in and process the amount of energy it needs to perform daily activities. If the body takes in more calories than it needs, it stores these calories as adipose tissue, or fat, for later use. In earlier times, this storage of calories by the body helped people survive through periods when little or no food was available (famine). During times of famine, the body burned its fat stores to obtain the energy it needed to perform normal activities. If people did not have these fat stores, they would starve during times when less food was available. 

Decreases in physical activity can lead to weight gain. Ultimately, all the calories you eat are not utilized, or burned off. Calories that are not utilized are stored as fat tissue, which... 

Team sports, such as volleyball or softball, are other options for increasing activity levels. A person engaging in any strenuous exercise should take caution at first, so as to not strain the body and cause injury. Table 8.1 lists some activities that can help a person expend energy and burn off calories. 

Daily energy requirements for children are approximately 150% of basal metabolic rate with additional calories to support activity and growth (Table 57-5). Requirements increase with fever, sepsis, major surgery, trauma, burns, long-term growth failure, and chronic conditions (e.g., bronchopulmonary dysplasia, congenital heart disease, and cystic fibrosis). 

Muscle tissue converts to fat as a natural aging process. This reduces your basal metabolic rate, causing you to use fewer calories. Increasing your level of activity prevents some muscle from converting to fat, burns more calories, and helps keep your metabolic rate up. 

You ll control your weight more easily and be able to eat more. Not only do you burn calories during physical activity, but the body s metabolism also remains revved up for hours afterward. In addition, as fitness levels increase, you ll build more lean muscle tissue. Since only muscle tissue can burn calories, acting as the body s furnace, you ll be able to consume more food without gaining weight. You ll find more about this in the weight loss chapter. 

The liver also plays a central role in lipid metabolism. When excess fuel is available, the liver synthesizes fatty acids. These are used to produce triglycerides that are transported from the liver to adipose tissues by very low density lipoprotein (VLDL) complexes. In fact, VLDL complexes provide adipose tissue with its major source of fatty acids. This transport is particularly active when more calories are eaten than are burned During fasting or starvation conditions, however, the liver converts fatty acids to acetoacetate and other ketone bodies. The liver cannot use these ketone bodies because it lacks an enzyme for the conversion of acetoacetate to acetyl CoA. Therefore the ketone bodies produced by the liver are exported to other organs where they are oxidized to make ATP. 

MINUTES OF ACTIVITY NEEDED TO BURN-UP FOOD CALORIES... 

PHYSICAL ACTIVITY AS AN ADJUNCT TO DIETARY PRACTICES. The need for following a carefully controlled diet is lessened somewhat by exercising enough to burn off at least 300 to 500 extra Calories (kcal) daily. Fig. P-35 shows that women who engaged in recreational physical activities were able to keep trim while consuming more calories than those whose activity levels were lower. 

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