TABLE OF CONTENT

CERTIFICATION

DEDICATION

ACKNOWLEDGEMENT

TABLE of CONTENT

CHAPTER ONE

INTRODUCTION

1.1     Background information

CHAPTER TWO

TYPES OF FIBER

2.1 Soluble fiber

2.2 Insoluble fiber

2.3 Health Benefit of Dietary Fiber

2.4  Effect of Dietary Fiber on gastro intestinal function

2.5 Dietary Fiber and the immune system

2.6 Daily Intake of the Dietary Fiber

2.7     Obesity

CHAPTER THREE

THE ROLE OF FIBER IN THE MANAGEMENT OF OBESITY

3.1: Dietary Fiber and Obesity

3.2 Dietary Fiber Intake and Weight  Management

3.3 Weight management through consumption of fruits and vegetables

3.4 Fiber and Glucose metabolism

3.5 The Role of Dietary Fiber on diabetes prevention and management

CHAPTER FOUR

SUMMARY AND CONCLUSION

4.1 Summary

4.2 Conclusion

References

CHAPTER ONE

INTRODUCTION

1.1 Background of the Information

Dietary fiber is a plant subunits that is not being degraded to absorbable subunits in the small intestine by alimentary enzymes found  in human being (Spiller, 2019). On the other side, (AACC, 2001) defined dietary fiber as edible part of plant or carbohydrates analogues that are resistant to digestion and absorption in the small intestine with complete or partial fermentation in the large intestine. Dietary fiber includes polysaccharides, Oligosaccharides, Lignin and associated plant substances.

Fiber are mainly found in fruits, vegetables, whole grains and legumes, it is probably best known for its ability to prevent or relieved constipation (Kim, 2016). Fiber is also known as Roughage or bulk, which include the parts of plant foods the body can’t digest or absorb  unlike other food component such as fats, proteins or carbohydrates which the body breaks down and absorbs fiber. Fiber isn’t digested by the body instead, it passes relatively intact through the stomach, small intestine and colon out of the body (Duyff, 2017).

Generally, dietary fibers are non-starch polysaccharides including (lignin). Health benefits of the consumption of fiber rich foods ranges from prevention and treatment of obesity, reduction of blood glucose and cholesterol level, glycemic regulation and prevention and intestinal disease like constipation, hemorrhoid, diverticular disease and colon cancer (Marlelt and Burney et al., 2002).

According to recommended dietary allowance (RDA), the dietary fiber of 35g/day is recommended for health adults (Lairon, and Arnault et al., 2005: Alfieri and Pomerleau et al., 2009). A recent  study shows the gradual reduction of dietary fiber consumption and much lower intake of dietary fiber 25g/days in  western countries has been reported (Viuda and Lopez Maneos et al., 2010). On the contrary, the epidemiological and cross sectional studies indicate that lower intake of dietary fiber is associated with obesity development (Alfieri and Pomerleau et al., 2009).

Obesity is one of the risk factors for morbidity and mortality including type 2 diabetes, cardiovascular, osteoarthritis, malignant and metabolic diseases, while the number of obese people is increasing with time (Pi, 2009).  (Nguyen and Lau, 2012) reported that approximately 1.5 billion adults are overweight or obese around the world, and obesity is being concerned as a global epidemic (Ginter and Simko, 2012). It is clear that obesity is a medical issue, which results in more cost on health care system in both development and developed countries (Magnusson, 2009), moreover, treating obesity through weight management is very important but notoriously difficult ( Ross, 2010).

With respect to their solubility in water, dietary fiber can be classified as soluble and insoluble, while their technological functionality and nutritional effects of dietary fibers are mainly composed of non-cellulosic polysaccharides (pectin, gums, mualage and hemicelluloses) and forms dispersion in water, thereby facilitates formation of viscous gels into the gastrointestinal tract, which slows gastric emptiness. These fermentation soluble fibers are associated with metabolism of carbohydrates and lipids and its found in large amounts in fruits and seaweed. Furthermore, insoluble fibers increase fecal volume up to 20 times because of its  water retention capacity and are mainly composed by cellulose, hemicellulose and lignin. This type of fiber is found mainly in vegetables, grains, legumes and fruits (Lecumberic and Mateos et al., 2007, Matos and Chambilla., 2010) and help to reduce concentration and contact time of potential carcinogens with the intestinal mucosa (Kim, 2016). In addition to the different sources of fibers (fruits, plants, vegetables among others), there are by-product of these source which have good physiochemical properties like onion by products and bagasse which has a good balance between soluble and insoluble fraction (Benitez and Molla et al., 2012).