Diabetes Dietary Study- Low Carbohydrate and Low-Fat Diets in Type 2 Diabetes

Hemoglobin A1c (HbA1c) is a form of hemoglobin (a blood pigment that carries oxygen) that is bound to glucose. HbA1c level indicates blood glucose levels over the previous 2 - 3 months. HbA1c values between 4 and 5.6 are considered normal. HbA1c values greater than 6.5 indicate diabetes.

Hemoglobin A1c (HbA1c) is a form of hemoglobin (a blood pigment that carries oxygen) that is bound to glucose. HbA1c level indicates blood glucose levels over the previous 2 - 3 months. HbA1c values between 4 and 5.6 are considered normal. HbA1c values greater than 6.5 indicate diabetes.

Hemoglobin A1c (HbA1c) is a form of hemoglobin (a blood pigment that carries oxygen) that is bound to glucose. HbA1c level indicates blood glucose levels over the previous 2 - 3 months. HbA1c values between 4 and 5.6 are considered normal. HbA1c values greater than 6.5 indicate diabetes.

Change in body weight often reflects the effects of dietary changes. Generally, an increase in body weight is correlated with increasing blood glucose levels while a decrease in body weight correlates to decreasing blood glucose levels. Dietary changes that result in decreased body weight will be associated with better glucose control.

Change in body weight often reflects the effects of dietary changes. Generally, an increase in body weight is correlated with increasing blood glucose levels while a decrease in body weight correlates to decreasing blood glucose levels. Dietary changes that result in decreased body weight will be associated with better glucose control.

Change in body weight often reflects the effects of dietary changes. Generally, an increase in body weight is correlated with increasing blood glucose levels while a decrease in body weight correlates to decreasing blood glucose levels. Dietary changes that result in decreased body weight will be associated with better glucose control.

A bioelectrical impedance analysis scale is used to measure body fat. Having a higher proportion of body fat is associated with poorer blood glucose control.

A bioelectrical impedance analysis scale is used to measure body fat. Having a higher proportion of body fat is associated with poorer blood glucose control.

A bioelectrical impedance analysis scale is used to measure lean body mass. Having a higher proportion of lean body mass is associated with better blood sugar control.

A bioelectrical impedance analysis scale is used to measure lean body mass. A higher proportion of lean mass is associated with better blood sugar control.

If medication dosage is reduced, it generally indicates that blood glucose is better controlled. If dosage increases, it generally indicates that blood glucose was not well controlled.

If medication dosage is reduced, it generally indicates that blood glucose is better controlled. If dosage increases, it generally indicates that blood glucose was not well controlled.

If medication dosage is reduced, it generally indicates that blood glucose is better controlled. If dosage increases, it generally indicates that blood glucose was not well controlled.

Insulin sensitivity is calculated from the fasting blood glucose and insulin levels derived from laboratory tests. An increase in insulin sensitivity relates to better blood glucose control. A reduction in insulin sensitivity is related to poorer blood glucose control.

Blood level of total cholesterol measures cardiovascular risk. Total cholesterol is reduced with weight loss. The change would be an indication of reduction in cardiovascular risk.

Blood level of total cholesterol measures cardiovascular risk. Total cholesterol is reduced with weight loss. The change would be an indication of reduction in cardiovascular risk.

Blood level of high density lipoprotein (HDL) cholesterol, measures cardiovascular risk. HDL cholesterol is expected to increase with weight loss. The change would be an indication of reduction in cardiovascular risk.

Blood level of high density lipoprotein (HDL) cholesterol, measures cardiovascular risk. HDL cholesterol is expected to increase with weight loss. The change would be an indication of reduction in cardiovascular risk.

Low density lipoproteins (LDL) cholesterol measures cardiovascular risk. LDL cholesterol is expected to be reduced with weight loss. This change would be an indication of reduction in cardiovascular risk.

Low density lipoprotein (LDL) cholesterol measures cardiovascular risk. LDL cholesterol is expected to be reduced with weight loss. This change would be an indication of reduction in cardiovascular risk.

Blood Triglyceride levels measure cardiovascular risk. Triglycerides are expected to be reduced with weight loss. This change would be an indication of reduction in cardiovascular risk.

The blood level of triglycerides measures cardiovascular risk. Triglycerides are expected to be reduced with weight loss. This change would be an indication of reduction in cardiovascular risk.

Dietary intake is assessed using the Dietary History Questionnaire (DHQ), a web-based food frequency questionnaire. Participants select the serving size and frequency of intake for the foods listed. The items listed and serving size choices are derived from the National Health and Nutrition Examination Survey (NHANES). Calculations of total energy (calories) consumed are based on the nutrient values from NHANES. It is anticipated that a decrease in calorie intake would result in body weight reduction which normally correlates to increased blood glucose control. Likewise, an increase in calories generally result in body weight increase which correlates to decreased blood glucose control.

Dietary intake is assessed using the Dietary History Questionnaire (DHQ), a web-based food frequency questionnaire. Participants select the serving size and frequency of intake for the foods listed. The items listed and serving size choices are derived from the National Health and Nutrition Examination Survey (NHANES). Calculations of total energy (calories) consumed are based on the nutrient values from NHANES. It is anticipated that a decrease in calorie intake would result in body weight reduction which normally correlates to increased blood glucose control. Likewise, an increase in calories generally result in body weight increase which correlates to decreased blood glucose control.

Dietary carbohydrate intake is assessed using the Dietary History Questionnaire (DHQ), which is web-based food frequency questionnaire. Participants select the serving size and frequency of intake for the foods listed. The items listed and serving size choices are derived from the National Health and Nutrition Examination Survey (NHANES). Calculations of total intake (in grams) of carbohydrates are based on the nutrient values from NHANES. It is anticipated that an increase in carbohydrate intake would result in an increase in blood HbA1c level, and a decrease in carbohydrate intake would result in a decrease in the blood HbA1c level.

Dietary carbohydrate intake is assessed using the Dietary History Questionnaire (DHQ), which is web-based food frequency questionnaire. Participants select the serving size and frequency of intake for the foods listed. The items listed and serving size choices are derived from the National Health and Nutrition Examination Survey (NHANES). Calculations of total intake (in grams) of carbohydrates are based on the nutrient values from NHANES. It is anticipated that an increase in carbohydrate intake would result in an increase in blood HbA1c level, and a decrease in carbohydrate intake would result in a decrease in the blood HbA1c level.

Dietary fat intake is assessed using the Dietary History Questionnaire (DHQ), which is web-based food frequency questionnaire. Participants select the serving size and frequency of intake for the foods listed. The items listed and serving size choices are derived from the National Health and Nutrition Examination Survey (NHANES). Calculations of total intake (in grams) of fat (saturated fat, monounsaturated fat and polyunsaturated fat) are based on the nutrient values from NHANES. It is anticipated that an increase in fat intake would result in an increase in total and LDL blood cholesterol levels, and a decrease in fat intake would result in a decrease in total and LDL blood cholesterol levels.

Dietary fat intake is assessed using the Dietary History Questionnaire (DHQ), which is web-based food frequency questionnaire. Participants select the serving size and frequency of intake for the foods listed. The items listed and serving size choices are derived from the National Health and Nutrition Examination Survey (NHANES). Calculations of total intake (in grams) of fat (saturated fat, monounsaturated fat and polyunsaturated fat) are based on the nutrient values from NHANES. It is anticipated that an increase in fat intake would result in an increase in total and LDL blood cholesterol levels, and a decrease in fat intake would result in a decrease in total and LDL blood cholesterol levels.

Dietary protein intake is assessed using the Dietary History Questionnaire (DHQ), which is web-based food frequency questionnaire. Participants select the serving size and frequency of intake for the foods listed. The items listed and serving size choices are derived from the National Health and Nutrition Examination Survey (NHANES). Calculations of total intake (in grams) of protein are based on the nutrient values from NHANES. It is anticipated that an increase in protein intake (relative to carbohydrate) will result in loss of body fat and reduction in body weight, while a decrease in protein intake(relative to carbohydrate) will result in increased body fat and body weight.

Dietary protein intake is assessed using the Dietary History Questionnaire (DHQ), which is web-based food frequency questionnaire. Participants select the serving size and frequency of intake for the foods listed. The items listed and serving size choices are derived from the National Health and Nutrition Examination Survey (NHANES). Calculations of total intake (in grams) of protein are based on the nutrient values from NHANES. It is anticipated that an increase in protein intake (relative to carbohydrate) will result in loss of body fat and reduction in body weight, while a decrease in protein intake(relative to carbohydrate) will result in increased body fat and body weight.

Physical activity was assessed using the Modifiable Physical activity Questionnaire (MAQ) with the 7-Day Physical Activity Recall interview. Participants were asked to provide information about the frequency, duration and intensity of various physical activities. MAQ responses and 7-day recall data were coded and entered into software program, which was designed to calculate average daily energy expenditure. Participants were instructed to avoid changing physical activity while in the study because change in physical activity could confound assessment of the dietary questions. An increase in physical activity could increase loss of body weight and reduction in blood HbA1c. A decrease in physical activity could increase body weight and increase HbA1c.

Physical activity was assessed using the Modifiable Physical activity Questionnaire (MAQ) with the 7-Day Physical Activity Recall interview. Participants were asked to provide information about the frequency, duration and intensity of various physical activities. MAQ responses and 7-day recall data were coded and entered into software program, which was designed to calculate average daily energy expenditure. Participants were instructed to avoid changing physical activity while in the study because change in physical activity could confound assessment of the dietary questions. An increase in physical activity could increase loss of body weight and reduction in blood HbA1c. A decrease in physical activity could increase body weight and increase HbA1c.

Quality of Life is assessed using the Diabetes Quality of Life (DQOL) questionnaire. The DQOL questionnaire contains 62 items which participants rank from 1(very satisfied) to 5 (very dissatisfied). The score gives an indication of participants' satisfaction with treatment in terms of level of well-being and disability. The total score ranges from 0 to 310. The score is negatively correlated to Quality of Life with higher scores indicating higher dissatisfaction and therefore, lower perceived Quality of Life. It is expected that reduction in the blood HbA1c level will be associated with an increase in the Diabetes Quality of Life (i.e. a decrease in DQOL score), and an increase in the HbA1c level will correlate to a lower Diabetes Quality of Life (i.e. an increase in DQOL score).

Quality of Life is assessed using the Diabetes Quality of Life (DQOL) questionnaire. The DQOL questionnaire contains 62 items which participants rank from 1(very satisfied) to 5 (very dissatisfied). The score gives an indication of participants' satisfaction with treatment in terms of level of well-being and disability. The total score ranges from 0 to 310. The score is negatively correlated to Quality of Life with higher scores indicating higher dissatisfaction and therefore, lower perceived Quality of Life. It is expected that reduction in the blood HbA1c level will be associated with an increase in the Diabetes Quality of Life (i.e. a decrease in DQOL score), and an increase in the HbA1c level will correlate to a lower Diabetes Quality of Life (i.e. an increase in DQOL score).