Conversely, fat feeding induces a higher rate of fat oxidation and a rapid repletion of muscle triacylglycerol stores Hawley, 2000. Accordingly, there might be some advantage to manipulating the diet to modify the pattern of fuel utilization to preserve or enhance performance. Currently, however, evidence in support of this theory is not convincing. A recent review of the literature concluded that fat adaptation over one to three days was not sufficient to elicit the purported metabolic shift in favor of fat utilization Burke and Hawley, 2002.
Likewise, fat adaptation over a longer period more than seven days did not provide performance benefits, and in some cases led to performance decrements. Two studies compared the effects of high-fat versus high-carbohydrate feeding on custom essay writing help outcomes during endurance training. During military operations, high energy expenditure is likely to occur in the context of an energy deficit.
None of the studies cited above considered the dual burdens of intense physical work and energy deficit on physical performance. This macronutrient mix was sufficient for the men to complete their task. Another study with distance runners varied the amount of dietary fat 17 percent, 31 percent, or 44 percent energy as fat to maximize energy and nutrient intakes. Energy intakes were lower than energy expenditure under all feeding conditions, over approximately 30 days. However, energy intakes were higher on the medium- and high-fat diets, and subjects reported being less hungry on them.
For the purposes of energy delivery, it seems desirable to provide 30-40 percent of the energy in the ration as fat. Increasing the fat beyond this level does not appear to improve physical or cognitive performance. In addition, a period of 14-21 days is needed to metabolically adapt to a high-fat diet, which is beyond the period of intermittent use for this ration Phinney et wgiting. This level of total fat will likely provide acceptable palatability while serving as an important source of energy. An ongoing concern for the military is that soldiers do not eat enough during field operations IOM, 1995particularly during high-intensity combat situations Popper et al.
Intense physical activity and stress are known to reduce food intake in trained athletes King et al. Again, this combination of factors is rarely encountered outside the military context and has been seldom studied. Since both hunger and the motivation to eat may be compromised in soldiers during high-intensity field operations, it seems prudent to maximize the palatability of the ration to the extent possible.
It is well known that taste is a primary determinant of food choices Glanz et al. Energy-dense foods custtom as fats are generally preferred over low-energy foods and seem to enhance overall food intake Drewnowski, 1997. The biological and personal factors that contribute to these differences writinng not well understood and need further study. For the purposes of this report, typical intakes could be considered as an index of acceptable levels of fat in the diet.
The mean estimated fat intake of young wrting men in the general population is 33 percent IOM, 2002a. Also, evidence from population studies suggests that custom essay writing help providing less than 30 percent energy as fat can be well tolerated, particularly custom essay writing help highly motivated individuals. The FSRs, which are under development by the USARIEM, provide approximately 27 percent energy as fat.
The military reports that FSRs are almost completely consumed in limited field tests personal communication, Whether the FSR provides the preferred level of fat for elite war fighters is unknown and should be ascertained in future studies. Nevertheless, based on previous experience, it is reasonable to assume that a ration providing 22-25 percent energy as fat will be relatively well accepted by soldiers in the field. Every effort should be made to optimize fat content and palatability of the ration design. The polyunsaturated fatty acids PUFA omega-6 n-6 and omega-3 n-3 are essential in the eessay diet.
The effects of fatty acid type, including n-3 and n-6 fatty acids, on physical and cognitive performance, immune function, and gene expression. There is some evidence that feeding n-3 fatty acids improves endurance performance in rats Ayre and Hulbert, 1996 and increases aerobic capacity esssay intracellular fatty acid transport in skeletal muscle Esday et al. Other evidence suggests that n-3 fatty custom essay writing help, especially in combination with protein supplements, increase muscle mass and protect against muscle wasting in cancer patients Barber et al.
Although these findings are provocative, they have little application to custom essay writing help military context at this time.uk essay writer write my physics paper i pay you online college essay service essay writers uk custom essay service for children