Table of Contents
Impact of Nutrition on Health
Mortality and Morbidity Trends Due To Nutrition Imbalance
An Overview on Critical Nutrition Disorders
Food Laboratory and Processing
Food Industry, Policy and Regulation
The course in environmental impact assessment concentrates on the scientific aspects of food, emphasizing reasons for procedures used and phenomena occurring in food preparation.
The course also elaborates the public health orientations in the regulation and policy that pertains food supply, quality assessment and assurance.
- To understand the scientific foundation of food science
- To recognize food pairing and that food choices in meal management have nutritional, cultural, psychological, economic, and safety influences
- To understand sensory and objective food evaluation
- To comprehend the scientific principles utilized in the preparation of carbohydrate, protein, and fat rich foods as well as in the complex system of batters and dough.
- To obtain proficient understanding of the regulations, policies and laws that concerns food supply.
Nutrition and health are coherent when it comes to maintaining or supporting the living human systems (lindlahr 1940). The health related complications in humans if we are to consider proximate estimations arising from different clinical analyses show a shocking percentage of about 80% of these arising from matters to do with nutrition.
Though our study in nutrition and health is not mainly based on this shocking trend it is an international aim to pursue health and if the methods undertaken are to be realistic then there is a crucial need to extend our observations and strategies towards the nutrition factors that are characteristic to all human societies. The further shocking issue in the global nutrition trend is the serious attention towards nutrition in the old aged, infants and nursing mothers than in the youth and the ages between 25 to 50 years.
As the study will show from the various world surveys, that these are not the only nutrition issues causing tension but there still exist more far reaching factors that grievously shift the basic nutrition patterns of humans to the non-healthy patterns. Among these factors are; levels of education, economic status, cultural and ethnic influence, religious influence, the food industry plus policy and regulations as controlled by the regional governments. Perhaps one of the chief factor or goal that was supposedly to be addressed in the millennial world campaign by the world states in some of their conventions had to be the nutrition though as our we know few or completely no convention was aimed at addressing this problem but instead politics and world economics have always dominated these conventions.
The science of nutrition shows that our body systems are dependant of the daily nutrients ingested and these substances act as the building blocks for our living systems, energy producing factors and great contributors towards body maintenance and repair. The study of the fundamentals in human nutrition and health therefore, opens us to wide range of topics that address most of the key issues in the nutrition detailing the body metabolism and the socio-economic factors in this criterion.
Basic Concepts in Nutrition: Nutrition, Kilocalories, and Nutrients
Nutrition science is a new subject introduced to man’s attention after the evolution of biology and chemistry. However, it is established that nutrition gained its greatest momentum within the 20th century during which the scientists outlined tow equivocal phases in characterizing this science.
In the starting phase which also acted as the foundation underlying the research in nutrition science, they were able to discover and characterize the various vitamins in which case their deficiency syndromes were described more in details. Also during this initial phase the recommended and required dietary nutrients were analyzed after which they were estimated according recommended dietary allowances (RDAs).
Additionally, in 1997 the recommended dietary allowances were further formulated using volumes containing dietary reference intakes which included extreme quantities of nutrient intake beyond the recommended ones for a health persons to such amounts that tough excessive but they present no detrimental effects to health in man. This also on the contrary characterized the second phase of the idealized modern day science of nutrition (Goldman: Cecil medicine 23rd edition).
The second phase conceptually concentrates on the dietary reference intakes (DRIs). These in the modern perspective of nutrition science develops evidence that ramifies the dietary relationships alongside the nutrition profile as main precursors for diseases that have stigmatized the health complications within the international community for instance cancer, and the coronary heart disease of which these two are haunted as the principle cause of silent death chiefly in the western states.
The term nutrition refers to the science that involves the study of nutrients in food their composition, role and metabolism in the living system. Therefore, nutrition is not enclosed to food substances and diet but it also broadens in the analysis of the body physiology as the various food substances channels through the digestive tract after ingestion and its final destination during absorption and assimilation.
Nutrition science seems to be taking a basic position in health sciences as it turns up to resolve most of the questions about a certain number of body complications. In this case, the health professionals have progressively been able to conceptualize certain ideas and theories as they tend to be interconnected with nutrition issues while solving the critical threats posing challenge against health wellness in man. The evolution of modern science have experienced the emergence of theories and concepts that from time to time has strengthened the principle of nutrition in science study and these have also been further supported by experimental analysis demographic survey results, and more so the real life experiences as seen in different individuals.
The scientific discoveries that have proved the fundamentality of nutrition in human science have no basis on superstitions as it has been the case in science such as the big-bang theories but rather more visible and non-fictions (Thompson, 1910).
This is so because nutrition derives its support and chief position in human science on tangible evidence, which is not limited to laboratory experimentations but even much more in the common environment around us. Our lives are key addresses to the modes of our nutrition and to be more frank it can be asserted that our health status act as mirrors through which we view or observe the discipline in our feeding. These days it has been so much materialized for instance in the case of obesity that the outward appearance in weight, skin texture and other observable features as symbols of nutrition orientations in individuals which scientifically may not be the right case yet when analyzed this concept and assertion may 60% be confirmed true clinically. However, before jumping to non-scientific conclusions there is a gap that we should consider vital and be left filled which actually opens us to some fundamentals in the process of feeding in man; its pillars, pathway and the role it plays in human existence.
It should be noted that feeding is not restricted to animals but instead to all the five kingdoms of the living things, as they have been outlined with plants and bacteria inclusive.
A brief overview of feeding in organisms
Feeding according to nutrition refers to the intake of food substances from the surrounding environment that contains a nutritious value into the body of an organism. Remember that in this case the term organism is being used in its primary denotation where it means a living thing hence asserting that feeding is a life process general for all the living organisms.
From scientific points of view, feeding has been categorised into two forms; autotrophic and heterotrophic which sometimes are also used to distinguish between plants and the animals though this pattern of classification have of recent been dropped due to the fact that though some organisms are not plants they show distinctive features that are not possessed by animals either. The autotrophic form of nutrition refers to the ability of an organism to synthesize its own food by using the available natural resources and this is rendered to the green plants. The green plants through the process of photosynthesis are able to build up food substances from common natural elements such as carbon, and elements of water by the use of solar energy absorbed by the green pigment; chlorophyll which is located in the chloroplasts of their cells. The light energy from the sun is used to build up bonds between the constituents elements that combine to form a food compound that can either be simple or complex.
However, unlike the autotrophic form of nutrition in plants, the animals exhibit a more dependant form of nutrition i.e. heterotrophic nutrition in which case the organism lucks the biological mechanisms of synthesizing its own food. The animal in this case therefore, can only use other organisms for its sources of food and nourishment due to its inability to convert the available natural elements into food compounds.
The main difference that offsets the position of these two distinct categories of organisms in feeding originates from the cytological differences.
The protoplasm of the plant cell is mainly saturated with the chloroplasts which act as cellular pockets for the chlorophyll pigment that plays a vital role in the absorption of light energy emitted from the sun whereas that of the animal cell is completely colourless due to the absence of chloroplasts. Some non-plant organisms such as some bacteria however, contain a particular type of chlorophyll that enables them to trap light for synthesis of organic compounds in the process called chemosynthesis. These bacteria also derive energy from chemical processes around them, which they then use in the formation and manufacture of food substances.
The pathway of food through the gastrointestinal tract
The animals take in food substances by ingestion through the mouth from where the substances are subjected to breakdown both chemically and mechanically in the process generally referred to as digestion. The process of digestion can either be physical, in which case the complex ingested food substrates are only broken into small molecules that can further pass through the slander channels of the alimentary canal (also known as the digestive tract). In this case, there is no altering the chemical nature of the ingested food. This physical digestion involves processes like;
- Mastication; which is the chewing action of the teeth as supported by the voluntary upward and downward movements of the jaw bones to grind and crush food on the surfaces of the teeth.
- Peristalsis; which are the wavelike contractions and relaxations of the esophagus and the intestines to soften food and propel it in the forward direction for further processes.
Food from the mouth after being acted on by the chewing action of the teeth is the sent to the esophagus due to the pressure exertion by the tongue and the further support by the roof of the buccal cavity, which also forms food into a ball-like substance, called a bolus. During swallowing, the larynx that opens into the trachea or wind pipe is protected by the glottis which is covered by the movements of the epiglottis so that no solid particles enters the respiratory tract. All this protective processes for the delicate tissues of the respiratory tract is involuntary under the control of the cerebrum of the brain.
While in the esophagus food is pushed forward ways by the wave-like motions of the walls and opened into the stomach by the cardiac sphincter muscle. The stomach walls secret the gastric juice that contains;
- Hydrochloric acid; produced by the goblet cells and it provides the acidic medium for the protein enzymes and disinfects food from all germs and disease causing bacteria.
- Mucus; produced by the oxyntic cells and it lubricates the walls of the stomach during contractions and movements. Mucus also protects the walls of the stomach from self-digestion by the protein enzymes.
- Protein enzymes; produced by the peptic cells and they carry out the chemical digestion of the protein food arriving in the stomach by converting it into peptides, and casein.
However, chemical digestion also takes place within the mouth for starch food as effected by the salivary amylase enzyme breaking and converting starch into maltose sugar. After physical and chemical digestion in the stomach, the pyrollic sphincter then releases food shortly towards the duodenum for further digestion of the undigested food. The pancreas organ release the pancreatic juice after stimulation and the juice contains the following substances;
- Pancreatic amylase; which is an enzyme that digests carbohydrates and continues the digestion of maltose sugar which had been previously terminated by the acidity of the stomach.
- Pancreatic lipase; which is intestinal another enzyme that breaks down the lipids into fatty acid molecules and simple glycerol.
The enzymes are chemical substances made up of organic constituents mainly proteins in nature and their role is to catalyze or speed up the rate of metabolic reactions in the body with digestion inclusive. The enzymes are produced from goblet cells of the gut and their activity is specific in nature and mediums of PH.
The different food substances are digested in specific regions of the gut in which a suitable PH medium can be located for the enzyme activity such as the main digestion for proteins that takes place in the stomach due to the acidic medium that is favorable for protein enzymes.
Absorption and assimilation of food in the gut
Both the physical and the chemical digestion of food renders the molecules a small size and an absorbable state that can pass through the small internal pores till the reach their final destination for use or storage in the body.
The process of absorption takes place in small minute molecules of the various food types such as the monosaccharide glucose for carbohydrates, amino acids for proteins, and fatty acids/glycerol for proteins and these have different channels of passage during their absorption though the ileum or small intestines play the greatest role in the process of absorption. Hence the main importance of the enzyme is realized at this stage as determinants for the particular and specific food molecule to be build up from a particular food type and therefore their absence in this criteria will present a considerably vast inhibition in the general body metabolic progress.
However, it should be noted that not all food types are digested in the body but some are directly absorbed across the walls of the gut without digestion. For example the mineral ions, vitamins and water whereas the dietary fibers or roughages are not digested in the body chemically due to their chemical composition that require the cellulose enzyme for digestion. The cellulose-digesting enzyme is not found in human guts hence the roughages are egested in the same chemical nature though their physical nature is always altered by physical processes caused in the gut.
The ileum is adopted to the absorption function due to the following anatomical features;
(a) It is a very long slander tube structure with the length approximating to about 2meters long a feature that provides a large surface area for the absorption of the already digested food molecules in the endothelium.
(b) The ileum is also internally made up of finger-like projections called the villi, which mainly allow the absorption of the end products for lipid and carbohydrates. The villi are suitably made of thin epithelial covering layers that allows easy passage of food molecules with very little resistance. The villi are further surrounded and covered with the microvilli, which also propel food during absorption to make the process quick and fast.
(c) In addition to the above is the juicy medium located inside the lumen of the ileum that allows the dissolving of the semi-solid food particles there by converting them into the flexible liquid state that can easily be absorbed via the pores of the lumen walls. The juicy medium in the ileum is contributed by the intestinal juice or succus-entericcus also secreted by the gut walls and it contain the digestive enzymes which finalize the digestion of all the ingested food substances.