Carbohydrates Versus Fats

We report a study designed to demonstrate the dietary influence on metabolic processes. The study included experiments to verify whether different meal types (in this case, carbohydrate-rich or fat-rich) would impact a person’s blood biochemical parameters such as glucose, triglycerides and urea.

Your task is to write a discussion that explains the results of the study. To complete this task, you will work individually to analyse changes in plasma glucose, triglyceride and urea levels in response to the consumption of a carbohydrate-rich versus a fat-rich meal.

Aim:

To study the changes in plasma glucose, triglyceride and urea levels in response to the consumption of a carbohydrate-rich versus a fat-rich meal.

Method:

Twelve healthy students from a research-intensive university volunteered to participate in this study. The study received ethics approval from the university, and volunteers gave their written consent to participate. Volunteers were divided into two groups: carb-rich and fat-rich. The carb-rich group consumed a meal of rice, white bread with jam, pasta with bolognese sauce and coke. In contrast, the fat-rich group consumed a meal of cheese pizza and diet soda. Both meals were isocaloric (having the same calorific value), meeting ~35% of the daily caloric requirement. The diets were monitored by a certified nutritionist.

On the morning of the experiment, all volunteers arrived at the clinic and ate a light breakfast. A sample of blood (pre-meal) was obtained at noon from all volunteers. At lunch time all volunteers went to a nearby restaurant for a supervised lunch. Six members ate the carb-rich diet while six other members ate the fat-rich diet. One hour after this meal, a second blood sample (post-meal) was obtained from all volunteers. Four hours later, a third sample of blood (evening) was obtained from the volunteers. All volunteers did not eat or drink anything else until the experiment was concluded.

The blood samples collected were labelled and stored on ice. Once all three sets of samples were collected they were analysed based on standard protocols approved by the clinical laboratory. The analyses included measurement of blood glucose, triglyceride and urea levels.

Results:

The blood glucose levels remained relatively constant all through the experiment in both groups of volunteers (Table 1).

Table 1. Blood glucose levels in both groups. Mean values +/-standard deviations in mg/dL.

Meal type

Pre-meal

Post-meal

Evening

Carb-rich

95.7+/-1.5

96.3+/-4.1

91.2+/-3.6

Fat-rich

94.7+/-3.0

97.8+/-4.1

96.2+/-1.8

The blood triglyceride levels are summarised in Figure 1. The triglyceride levels of those who consumed a fat-rich diet increased soon after lunch and continued to rise as shown from the evening sample. The triglyceride levels in those who consumed a carb-rich meal remained unchanged until after lunch and then increased by the evening.The blood urea levels are summarised in Figure 2. The urea levels remained constant in both groups until after lunch and increased significantly in those who consumed a fat-rich meal.

Task

Your task is to write a discussion that explains the results of the study. To complete this task, you will work individually to analyse changes in plasma glucose, triglyceride and urea levels in response to the consumption of a carbohydrate-rich versus a fat-rich meal. The discussion must include an explanation of all the results obtained in the study. In particular your discussion must include the following: In particular, you must discuss the following:

why blood glucose levels remain constant in both groups across all time points with emphasis on the counter-regulatory mechanisms and hormones that are involved in maintaining stable blood glucose levels;

why blood triglyceride levels fluctuate during the day and a hypothesis of why the triglyceride levels vary between the two groups; and

the significance of the blood urea levels in the two groups.

You must divide your discussion using the following subheadings:

Blood glucose

Blood trigly