The current ‘consensus’ is that weight loss can only occur through a conscious decreased intake of food and a conscious increased participation in physical activity. However the record of energy restriction at causing successful long term weight loss is poor and the nutritional literature does not support a role for forced energy restriction in successful long term weight loss. Restricting calories at the same time as increasing energy expenditure seems a logical thing to do to cause weight loss. Reducing the energy input while increasing the energy output would appear at first glance to have to force the body to use the energy reserves it possesses to meet its requirements. However, this does not happen because the body can counteract the changes with energy savings elsewhere. The hypothalamus can reduce the energy is wastes as heat, both following exercise and food intake. In addition, the hypothalamus can catabolise the skeletal muscle to reduce the resting metabolic rate and at the same time provide a source of energy for its daily requirements.
Therefor main problem with energy restriction and concomitant increased energy expenditure is that it causes body wasting. In particular the skeletal muscle of the body is catabolised and this can significantly reduce the muscle mass of the individual. Biologically fever produces similar effects to energy restrictive diets in that concomitant to a reduction in appetite comes an increase in energy expenditure. The response to acute infection includes fever (increase energy expenditure) and anorexia (decreased food intake). The cause of the reduced food intake is thought not to result from the increased body temperature seen in fever1. However, irrespective of the mechanisms, the result of the decreased food intake and increase energy expenditure in acute infection is a negative nitrogen balance and extensive wasting of the muscle of the body. This muscle wasting seen with fever is very similar to the wasting that occurs on low calorie diets when energy intake is restricted at the same time as performing increasing physical activity.
While it could be argued that fever is a condition of illness and should not be compared to weight loss in a normal ‘healthy’ person, it could also be argued that weight gain is also an illness caused by metabolic dysfunction. Evidence suggests that weight gain is caused by aberrations in the appetite and energy regulation pathways and this produces a systemic metabolic state whereby food in not efficiently utilised as energy and signal pathways regulating intake go awry. That it is understood medically that the anorexia and increased energy expenditure in fever is detrimental to long term health, the misunderstanding regarding the same changes in calorie restrictive diets is puzzling. The case of fever also highlights the power of the brain to control food intake, in both a positive and negative way. While it would not be expected for someone to override the suppression of appetite brought about by fever, it is expected that an individual should overcome the appetite stimulatory effect of a low calorie diet. Such thinking is in my opinion worthy of parody.
Dr Robert Barrington’s Nutritional Recommendation: The muscle wasting in fever is brought about by similar physiological changes to the muscle wasting seen in calorie restrictive diets. Both are a cause of long term ill health and an increased risk of mortality. Effective fat loss can only occur by consuming a healthy high quality diet, devoid of the metabolic poisons present in the typical Western diet. Trying to lose weight while maintaining a low quality diet will result in failure and misery.
RdB
