Metformin at the Cellular Level and Dosing for Diabetes Mellitus (DM)

Pediatric Inclusion Criteria: * Children 10-17 years. * Both genders (male and female) * All children must have a Primary Care Physician and/or an Endocrinologist who must be aware that the child under their care will be part of the study. * All children must have a Primary Care Physician and/or an Endocrinologist who is considering initiating metformin therapy now or in the near future as part of standard clinical care. * Naïve to metformin. * Either: Prediabetic children Or diabetic children under good glycemic control Pediatric Exclusion Criteria: * Children ages 10-17 who do not have parental consent and/or do not give assent * Children living in foster care * Children with allergies to foods in the breakfast menu * Children who currently consume any alcohol * Children on current antidiabetic medication or those who have been on any antidiabetic medication in the 3 months prior to enrolment * Children with a history of /or concurrent chronic disease (eg. heart, kidney, liver disease or any type of malignancy or pre-malignant condition) that required hospitalization within the last 6 months * Pregnancy * Refusal by a female participant who is of child bearing potential and sexually active to use contraceptive methods such as oral contraceptive pills, barrier methods and abstinence * Children weighing less than 36 kg * Children with any condition that increases the risk of lactic acidosis (e.g. cancer, infection, congestive heart failure, renal disease ) * Children with history of recent hospitalization for surgery, dehydration, sepsis, hypoxemia (within the past 6 months) * Children with history of weight loss, polyuria and polydipsia * Children who are currently enrolled in a weight management program * Children with known hypersensitivity to metformin * Children with a fasting blood glucose of \>180mg/dl * Children with a HbA1c level of ≥7% * Children with glycosuria * Children with clinical or laboratory evidence of hepatic disease- transaminase levels three times the upper normal range (Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT)) and/or a increased level of Gamma-glutamyltransferase (GGT), Prothrombin Time (PT), International Normalized Ratio (INR) from the reference normal range and a serum albumin less than the reference normal range of the Johns Hopkins Clinical Laboratories. * If iodinated contrast is used on a participant, due to possible acute alteration of renal function resulting in increased risk of lactic acidosis, the participant will be excluded. * Children with renal impairment * In children \>50kg, renal impairment is defined by a serum creatinine 1.4 mg/dl or higher in females or 1.5mg/dl or higher in males OR estimated Glomerular Filtration Rates (eGFR) ≤60mL/min by the Schwartz formula. * In children \<50kg, renal impairment is defined by eGFR \<100 mL/min by the Schwartz formula. * Children with acid-base disturbance as defined by serum bicarbonate levels less than 20mEq/L or greater than 29mEq/L. Adult Inclusion Criteria: * Adults 18-79 years * Both genders (male and female) * All participants must have a Primary Care Physician and/or an Endocrinologist who must be aware that the adult under their care will be part of the study * All participants must have a Primary Care Physician and/or an Endocrinologist who is considering initiating metformin therapy now or in the near future as part of standard clinical care. * Naive to metformin * EITHER: Prediabetic adults OR diabetic adults, under fair glycemic control: Adult Exclusion Criteria: * Pregnancy * Adults who are not able to understand the Informed Consent document and who are unwilling to do the study * Adults with allergies to any of the foods in the breakfast menu * Adults on current antidiabetic medication or on any antidiabetic medication in the 3 months prior to enrolment. * Adults with a history of /or concurrent chronic disease (e.g. heart, kidney, liver disease or any type of malignancy or pre-malignant condition) that required hospitalization within the last 6 months * Refusal by a female participant who is of child bearing potential and sexually active to use contraceptive methods such as oral contraceptive pills, barrier methods and abstinence * Adults with excessive current intake of alcohol (\>2 drinks/day for males and \>1 drink/day for females) * Adults who have engaged in binge drinking (\>5 drinks within a 2 hour period) in the last 3 months * Adults with history of recent hospitalization for surgery, dehydration, sepsis, hypoxemia (past 6 months) * Hypersensitivity to metformin. * Adults with fasting blood glucose of \>180mg/dl. * Adults with HbA1c level of ≥8% * Adults with glycosuria. * Adults with any condition that increases the risk of lactic acidosis (e.g. cancer, infection, congestive heart failure, renal disease ) * Adults with clinical or laboratory evidence of hepatic disease- transaminase levels three times the upper normal range (AST and ALT) and/or a increased level of GGT, PT, INR from the reference normal range and a serum albumin less than the reference normal range of the Johns Hopkins Clinical Laboratories. * If iodinated contrast is used on a participant, due to possible acute alteration of renal function resulting in increased risk of lactic acidosis, the adult participant will be excluded. * Adults with renal impairment as defined by a serum creatinine 1.4 mg/dl or higher in females or 1.5mg/dl or higher in males OR estimated Glomerular Filtration Rates (eGFR) ≤60mL/min by Modification of Diet in Renal Disease (MDRD) formula. * Adults with acid-base disturbance as defined as serum bicarbonate levels less than 20mEq/L or greater than 29mEq/L. Adult Obese Control Inclusion Criteria: * Age 18-79 * Both genders (male and female) * BMI \> 30 kg/m2 Adult Obese Control Exclusion Criteria: * Subjects previously or currently on any diabetes medication, including metformin, will be excluded. * Pregnancy * Subjects with history of or concurrent chronic disease (e.g. heart, kidney, liver disease or any type of malignancy or pre-malignant condition) that required hospitalization within the last 6 months will be excluded. * Adults with allergies to any of the foods in the breakfast menu * Adults with excessive current intake of alcohol (\>2 drinks/day for males and \>1 drink/day for females) * Adults who have engaged in binge drinking (\>5 drinks within a 2 hour period) in the last 3 months