Human Mitochondrial Stress-driven Obesity Resistance

Eligibility criteria for individuals with mitochondrial DNA mutations Inclusion criteria: \- Known mtDNA point mutations Exclusion criteria: * Use of antiarrhythmic medications or other medications which, in the opinion of the investigators, have the potential to affect outcome measures. * Diagnosed severe heart disease, dysregulated thyroid gland conditions, or other dysregulated endocrinopathies, or other conditions which, in the opinion of the investigators, have the potential to affect outcome measures. * Pregnancy Eligibility criteria for controls Exclusion criteria: * Current and regular use of antidiabetic medications or other medications which, in the opinion of the investigators, have the potential to affect outcome measures. * Diagnosed heart disease, symptomatic asthma, liver cirrhosis or -failure, chronic kidney disease, dysregulated thyroid gland conditions or other dysregulated endocrinopathies, or other conditions which, in the opinion of the investigators, have the potential to affect outcome measures * Daily use of tobacco products * Excessive alcohol consumption * Pregnancy