• The fasting blood sugar level [ Time Frame: Baseline and 4 weeks of intervention ]
  The previous study reported that high dietary fiber could decrease the fasting blood sugar in type 2 diabetes patient. The overweight female volunteer receive food supplement containing dietary fiber from Cassava should show the lower level of fasting blood sugar than the placebo-treated group after 4 weeks of intervention.
• The atherogenic index [ Time Frame: 4 weeks of intervention ]
  The atherogenic index is an index composed of triglycerides and high-density lipoprotein cholesterol. It has been used to quantify blood lipid levels and commonly used as an optimal indicator of dyslipidemia and associated diseases. The food supplement containing dietary fiber from Cassava might be able to decrease the atherogenic index in overweight female volunteer. The overweight female volunteer receive food supplement containing dietary fiber from Cassava should show the lower number of the atherogenic index than the placebo-treated group after 4 weeks of intervention.

• hemoglobin A1c concentration [ Time Frame: 4 weeks of intervention ]
  A hemoglobin A1c (HbA1c) test measures the amount of blood sugar (glucose) attached to hemoglobin. This result shows the average amount of glucose attached to hemoglobin has been over the past three months. The previous study reported that high dietary fiber could decrease the HbA1C in type 2 diabetes patient. The food supplement containing dietary fiber from Cassava might be able to decrease the HbA1C in overweight female volunteer. The overweight female volunteer receive food supplement containing dietary fiber from Cassava should show the lower HbA1C level than the placebo-treated group after 4 weeks of intervention.
• Homeostasis model assessment-insulin resistance (HOMA-IR) [ Time Frame: 4 weeks of intervention ]
  HOMA-IR was computed with the formula: fasting plasma glucose (mmol/l) multiplied fasting serum insulin (mU/l) divided by 22.5. Low HOMA-IR values indicate high insulin sensitivity, whereas high HOMA-IR values indicate low insulin sensitivity (insulin resistance). The overweight female volunteers receive food supplement containing dietary fiber from Cassava should show the lower HOMA-IR than the placebo-treated group after 4 weeks of intervention.
• Low-density lipoprotein (LDL) concentration [ Time Frame: 4 weeks of intervention ]
  LDL is considered bad cholesterol and a leading cause of atherosclerosis formation. The food supplement containing dietary fiber from Cassava might be able to decrease the LDL level in overweight female volunteer. The overweight female volunteers receive food supplement containing dietary fiber from Cassava should show the lower LDL concentration than the placebo-treated group after 4 weeks of intervention.
• High-density lipoprotein (HDL) concentration [ Time Frame: 4 weeks of intervention ]
  HDL is considered as good cholesterol and believed that it acts as a scavenger and carrying of LDL from the arteries back to the liver. The food supplement containing dietary fiber from Cassava might be able to increase the LDL level in overweight female volunteer. The overweight female volunteers receive food supplement containing dietary fiber from Cassava should show a higher HDL concentration than the placebo-treated group after 4 weeks of intervention.
• Triglyceride (TG) concentration [ Time Frame: 4 weeks of intervention ]
  TG is one type of fat in the blood which converted from the excess energy from the diet. A high triglyceride level combined with high LDL (bad) cholesterol or low HDL (good) cholesterol is linked with fatty buildups within the artery walls, which increases the risk of heart attack and stroke in an overweight person. The food supplement containing dietary fiber from Cassava might be able to decrease the LDL level in overweight female volunteer. The overweight female volunteers receive food supplement containing dietary fiber from Cassava should show the lower TG concentration than the placebo-treated group after 4 weeks of intervention.
• Cholesterol concentration [ Time Frame: 4 weeks of intervention ]
  The high level of cholesterol is a cause of atherosclerosis in the blood vessel. The food supplement containing dietary fiber from Cassava might be able to decrease the cholesterol level in overweight female volunteer. The overweight female volunteers receive food supplement containing dietary fiber from Cassava should show the lower cholesterol concentration than the placebo-treated group after 4 weeks of intervention.
• Body mass index (BMI) [ Time Frame: 4 weeks of intervention ]
  The food supplement containing dietary fiber from Cassava might be able to decrease the BMI in overweight female volunteer. The overweight female volunteers receive food supplement containing dietary fiber from Cassava should show the lower BMI than the placebo-treated group after 4 weeks of intervention.
• Gut microbes [ Time Frame: 4 weeks of intervention ]
  It has been reported that the dysbiosis can cause the alteration of glucose metabolism, lipid metabolism, and dyslipidemia. Moreover, the high fiber diet causes the elevation of good bacteria in the gut and exert many effects. The food supplement containing dietary fiber from Cassava might be able to increase the good gut microbes in overweight female volunteer. The overweight female volunteers receive food supplement containing dietary fiber from Cassava should show higher gut microbes than the placebo-treated group after 4 weeks of intervention.
• The consumption safety of food supplement containing dietary fiber from Cassava using Systolic and Diastolic Blood pressure [ Time Frame: 4 weeks of intervention ]
  If the supplement containing dietary fiber from Cassava is safe, the blood pressure should be within the normal range.
• The consumption safety of food supplement containing dietary fiber from Cassava using the electrocardiogram pattern and QT interval data [ Time Frame: 4 weeks of intervention ]
  If the supplement containing dietary fiber from Cassava is safe, the EKG pattern and the QT interval should be within the normal range.
• Consumption safety of food supplement containing dietary fiber from Cassava using blood chemistry [ Time Frame: 4 weeks of intervention ]
  The blood chemistry values including renal function test, liver function test, and electrolytes will be determined and the data will be expressed as the number of subjects presented with abnormal blood chemistry value.
• Consumption safety of food supplement containing dietary fiber from Cassava using hematolgical values. [ Time Frame: 4 weeks of intervention ]
  The hematological values including red blood cell, white blood cell, hematocrit, and platelet will be determined and the data will be expressed as a number of subjects presented with abnormal hematological value.

Cassava is one of the important industrial crops in Thailand. The leftover fiber of cassava is still valuable and can be used as a dietary fiber. The previous study demonstrated that dietary fiber containing cassava fiber was safe for consumption without any contamination of the cyanide and heavy metals. Moreover, the microbial contaminations were within the safety range. The toxicity study revealed that the LD50 of the cassava dietary fiber was more than 5 g/kg body weight (BW) and NOAEL was 3 g/kg BW. The NOAEL was used to calculate the human equivalent dose for determining the effect of cassava dietary fiber in a clinical study.

Cassava dietary fiber consists of water-insoluble fiber such as cellulose more than 50%. The previous study showed that insoluble fiber decreased the risk of type 2 diabetes and increased insulin release. Moreover, a high fiber diet also decreased the fasting glucose and HbA1C in type 2 diabetes volunteer. In addition, the effect of dietary fiber on the reduction of cholesterol was also reported. The previous study reported that the cassava dietary fiber could decrease the total cholesterol, triglyceride but increase high-density lipoprotein in a dyslipidemia rat model. Therefore, the cassava fiber might be the potential food supplement for the control of blood sugar and lipid profiles in human. However, less scientific data support the effect of cassava dietary fiber in human.

• Placebo Comparator: Placebo capsule
  Subject receive the Placebo product for 4 weeks.
  Intervention: Dietary Supplement: Cassava dietary fiber capsule
• Active Comparator: Cassava dietary fiber capsule 1.5 g/day
  Subjects receive Cassava dietary fiber capsule at the dose of 1.5 g/day for 4 weeks.
  Intervention: Dietary Supplement: Cassava dietary fiber capsule
• Active Comparator: Cassava dietary fiber capsule 3 g/day
  Subjects receive Cassava dietary fiber capsule at the dose of 3 g/day for 4 weeks.
  Intervention: Dietary Supplement: Cassava dietary fiber capsule

Inclusion Criteria:

• Healthy women age between 35-60 years old
• BMI 23-29.99
• Blood pressure <140/90 mmHg
• Fasting plasma glucose < 100 mg/dL

Exclusion Criteria:

• Presence of any chronic diseases
• Alcohol addict or consume more than 2 units/day
• Smoking more than 10 cigarettes per day
• Medication or herbal medicine usage within 1 month prior to the study
• Use any medication or food supplement which affect to outcomes
• Pregnant or breastfeeding women
• Athlete