Description

ABSTRACT

The glycemic index (GI) is a measure of the potential of foods containing the same amount of carbohydrate to raise ß-glucose concentration in the blood after a meal. This study was conducted to measure the glycemic index and glycemic load of staple foods used in Nigeria for the management of type 2 diabetes mellitus. Whole grain flours of wheat, millet and sorghum mixed with sardines (sardinops malanosticta) were prepared into meals in the laboratory of the Department of Food Science and Technology, Imo State University. Proximate composition of the flours was determined by using AOAC (1995) methods. Glycemic index (GI) was determined according to FAO/WHO (1998) recommendations using 10 respondents. Results showed that, cassava meal had the highest percentage of carbohydrate (83.31%) followed by sorghum (78.16%), wheat (72.60%) and finger millet (72.12%). There was a significant (p<0.05) difference in carbohydrate content between cassava and the other foods. Regarding GI, results showed that, wheat has (51), while finger millet (60.92) had medium GI values and Sorghum meal had the highest GI (65.71).

The variations in GI index values observed could be attributed to characteristics of the carbohydrate and the type of starch present in the foods. According to GIs data, undehulled wheat meal are recommended for the regular diet for the management of type 2 diabetes mellitus. Moreover finger millet and sorghum meals are also recommended to be consumed moderately in a diet. It is important to associate GL and GI data of Nigerians traditional foods for the management and the prevention of diabetes in Nigerian and in others countries sharing the same tradition foods.

 

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

CHAPTER ONE

INTRODUCTION

• Background Of Study
• Problem Statement
• Aim and objectives of the study
• Research hypothesis
• Significance of the study
• Scope of the study
• Limitations of the study
• Research question
• Project organisation

CHAPTER TWO

LITERATURE REVIEW

• Staple Food
• Millet
• Sorghum
• Wheat
• Carbohydrate
• Dietary carbohydrate
• Total carbohydrate
• Sugars
• Starch
• Dietary fibre
• Available carbohydrate
• Carbohydrate digestion
• Glycaemic index concept
• Glycaemic load concept
• Determination of glycaemic index
• Glycaemic Load and Health
• Glycaemic load and diabetes
• Glycaemic load and coronary heart diseases

CHAPTER THREE

3.0     MATERIALS AND METHOD

• Materials
• Method
• Chemical analyses
  • Proximate composition
  • Digestibility study
  • Oral test load
  • Fecal excretion
  • Glycemic index
• Recruitment of participants
• Screening of candidate
• Data collection
• Ethical considerations
• Statistical data analysis

CHAPTER FOUR

• RESULTS AND DISCUSSION
• Results
• Discussion

CHAPTER FIVE

• conclusion and recommendation
• REFERENCES

CHAPTER ONE

INTRODUCTION

1.1                                         Background of the Study

According to Jenkins et al (2018), glycemic index (GI) is known as a measure of the potential of foods containing the same amount of carbohydrate to raise β-glucose concentration in the blood after a meal. It compares the hyperglycemic effect of a meal with pure glucose or bread (Itam et al, 2012). Epidemiological studies have associated GI with the causation and treatment of chronic diseases, such as Type 2 diabetes mellitus, hypertension, cardiovascular diseases and cancer (Brynes et al, 2013). The GI concept also takes into account the effect of the total amount of carbohydrate consumed which is a glycemic load (GL). Therefore, glycemic load is a product of GI and quantity of carbohydrate eaten which indicates the amount of glucose available for energy or storage following a meal containing carbohydrate (Venn et al, 2017). GI values range from less than 20% to approximately 100% when using glucose as a reference (Ranawana et al, 2019).

Glycemic index acts as a scale which ranks the carbohydrate in foods depending on how they affect blood glucose levels in a span of 1 to 2 hours after a meal (Wolever et al, 2018). Its response to food which affects insulin response depends on the rate of gastric emptying, as well as on the rate of digestion and absorption of carbohydrate from the small intestines (Ostman et al, 2011). This implies that, while foods with elevated GI break down quickly during digestion and release glucose rapidly into the bloodstream the foods with lower GI usually take long time to get digested and absorbed resulting into slower and gradual changes in blood sugar levels (Mendosa, 2019). The lower glycemic response usually relates to a lower insulin demand and may improve glucose level over time [9]. A low-GI food will release glucose more slowly and steadily, which leads to more suitable postprandial (after meal) blood glucose readings. High glycemic index foods cause more rapid rise in blood glucose levels and are recommended for energy recovery after exercise or for a person experiencing hypoglycemia (Atkinson et al, 2018). The glycemic effect of foods depends on a number of factors such as the type of starch in the food (amylose versus amylopectin), physical entrapment of the starch molecules within the food, fat and protein content and organic acids or their salts in the meal [Wanjek et al, 2012].

Scientific evidence has shown that individuals who took a low-GI diet over many years had significantly lower risk of developing type 2 diabetes, coronary heart disease, and age-related muscular degeneration than others. Type 2 diabetes mellitus is a metabolic degenerative disease and if not properly managed can lead to a lot of complications. Sheard (2014) reported that, repeated glycemic rise following a meal may promote these diseases by increasing systemic glycative stress, other oxidative stresses, and direct increase in insulin levels. Many low- GI foods are relatively less refined and more difficult to consume than high-GI foods. The lower energy density and palatability of these foods are important determinants of their greater satiating capacity. Dietary factors such as fibers and glycemic load/index may affect plasma adinopectin through modulation of blood glucose, because a diet rich in some types of fiber can lower glucose concentrations whereas a diet high in glycemic index may increase blood glucose (Brand-Miller et al, 2019). A Study done by the European Association for Diabetes (American Diabetes Association, 2012) recommended high-fiber, low-GI foods for individuals with diabetes as a means of improving postprandial glycemia and weight control. A study from Harvard University indicated that, the long-term consumption of a diet with a high glycemic load and glycemic index was a significant independent predictor of the risk of developing type 2 diabetes (Godley et al, 2019). Other evidences have shown that a low-GI diet might also protect against the development of obesity, colon cancer and breast cancer [Ebbeling et al (2012) & Pawlak et al (2018)]. Since low-GI foods have been shown to improve blood glucose control in people with type 2 diabetes mellitus, to increase insulin sensitivity and β-cell function and to reduce serum triacylglycerol, and then they have been recommended to help guide food choices for diabetic and non-diabetic individuals (Wolever et al, 2012).

Widespread use of the GI, as recommended, requires a standardized method for determining the GI of foods that is valid and precise. In recent years, there has been a steady global increase in the incidence of non- communicable diseases, such as diabetes in both developed and developing countries, Nigeria inclusive. Selection of low-GI carbohydrate foods for meal planning for individuals with type 2 diabetes as recommended by FAO/WHO (2018) has remained pertinent in the long term management of T2DM. Practical implications of GI and nutritional recommendations that could be made on diets need clear knowledge of the GI values for various foods. There is how ever knowledge gap on the GI values for many staple foods in many parts of developing countries including Nigeria. This study was therefore designed as part of the efforts to fill that gap of knowledge. Results of this study will serve as basis for advising diabetic subjects of appropriate food selection based on GI and in planning public health education intervention on diabetes management.

1.2     Statement of the Problem

Diabetes mellitus is a chronic metabolic disorder with a strong hereditary basis, associated with blood glucose. Basically it is caused by the deficiency in the secretion of insulin of pancreatic cells. The two main types of diabetes classified by WHO are insulin dependent or Type 1 and non-insulin dependent diabetes or Type 2.

Diabetes mellitus is one of the most common syndrome from the cluster of Syndrome X affecting masses. However, diet remains the cornerstone for diabetic patients, especially non-insulin dependent diabetics. Whole grains coupled with millet based foods possess low glycemic index, which plays a major role in the management of hyperglycemia in diabetes.

According to Willet et al. (2012), the consumption of high glycaemic indices and high glycaemic load diets for several years might result in increased postprandial blood glucose spikes and excessive insulin secretion. This could lead to the loss of insulin-secreting function of the pancreatic β- cells, resulting in irreversible Type 2 Diabetes mellitus. In addition to this assertion, Ludwig and Daniel (2012) in a study state that, sustained spikes in blood sugar and insulin levels may lead to increased diabetes risk. Diabetes mellitus Type 2 is currently one of the most prevailing chronic diseases in the world and the number of people with the disease is stated to be increasing in every country. International Diabetes Federation (IDF) has estimated that 415 million adults globally, are presently living with the condition. Nonetheless, this is predicted that people having this condition would rise to 642 million by 2040. An estimated 14.2 million adults (aged 20-79) have diabetes in Africa, representing 6.7% (IDF, 2016). This prevalence can be minimized to a lower rate when people are made aware of the glycaemic indices and glycaemic loads of the foods they consume, as these play major roles in the development of this condition. When consumers are well informed on the rate at which the glucose in our local foods is released into the bloodstream, they will be very cautious about their choice of food and even the time they eat these foods as well as the amount they consume.

However, this work studies the glycemic indices of composite wheat, sorghum and millet meal.

1.3     Aim and objectives of the Study

The main aim of this study was to determine the glycemic indices of composite wheat, sorghum and millet meal. To achieve this, the study sought to;

1. Determine the glycemic load of composite wheat, sorghum and millet meal.
2. Perform proximate analysis of wheat, sorghum and millet meal.
3. Carryout the sensory analysis of the wheat, sorghum and millet meal.
4. Make a recommendation for food to be consumed moderately in a diet
5. Determine the digestibility of wheat, sorghum and millet meal.

1.4     Research Hypothesis

H0 = There is no significant difference in the glycemic load of glycemic indices of composite wheat, sorghum and millet meal.

H1= There is a significant difference in glycemic indices of composite wheat, sorghum and millet meal.

1.5     Significance of the Study

Essentially, the glycemic load, which is the product of the glycemic index and the carbohydrate content of a given food, may be more useful than only the glycemic index. This is because the glycemic load takes into account the portion size of the food as well as the carbohydrate content. Glycemic load is a significant factor in dietary programmes aiming at the metabolic syndrome, insulin resistance, and weight loss.

It is hoped that this study will come up with the optimal size of glycemic indices of composite wheat, sorghum and millet meal which when consumed will have no effect on the blood glucose level. Knowledge of the glycemic load of glycemic indices of composite wheat, sorghum and millet meal could serve as a guide to diabetics to choose these stable food with the best glycemic load.

This study may also inform nutritionists, dieticians and diet therapists on the glycemic indices of composite wheat, sorghum and millet meal recommend to prediabetics and diabetics when they counsel their clients.

This study will solve the problem of high intake of food containing large amount of carbohydrates. The study also will also make important contribution to future research by contributing to the existing literature particularly on nutrition.

1.6        Scope of the study

The research focused on glycemic indices of composite wheat, sorghum and millet meal and their impact on the blood glucose. This study investigated all the possible wheat, sorghum and millet meal that are consumed in the country and also analyzes the extent to which each of these affect the blood glucose level.

1.7     Limitations

The study determined the glycemic load of wheat, sorghum and millet meal. All the different staple foods; wheat, sorghum and millet meal were analyzed. Findings cannot be easily generalized for other carbohydrate foods. The study focused on the effect wheat, sorghum and millet meal has on blood glucose level after it has been digested and so healthy individuals were used for the study.

1.8      Research Question

1. What is the glycemic index for wheat, sorghum and millet meal?
2. What is the major cause of diabetes mellitus?

• Do wheat, sorghum and millet meal has high glycemic index?

 

1.9  Project Organisation

The work is organized as follows: chapter one discuss the introductory part of the work,   chapter two presents the literature review of the study,  chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.