Nutrition is a science that studies the relationship between diet, state of health and disease. The nutritionists are health professionals who specialize in this field. Are also the only highly trained health professionals able to provide advice and safe dietary interventions.
Between the extremes of optimal health and death from starvation or malnutrition, there are a variety of diseases that can be caused or alleviated by changes in diet. The gaps, excesses and imbalances in diet can produce negative impacts on health, which can lead to diseases such as scurvy, obesity or osteoporosis, as well as psychological and behavioral problems. Moreover, excessive ingestion of elements that have no apparent role in health (eg lead, mercury, dioxins, etc.) may incur toxic and potentially fatal, depending on the dose.
Would include the Krebs cycle in the processing of the components in the diet.
The science of nutrition attempts to understand how and why specific dietary aspects influence health.