Ketone bodies are a fuel source and signaling molecule that are produced by your body during prolonged fasting or if you consistently eat at low-carbohydrate diet. Blood ketones can be used as a source of energy during fasting and are used by your brain as an alternative source of fuel to glucose. Previous studies have found that ketones, when consumed in form of a supplement drink, can increase blood ketone levels and lower blood glucose, the amount of sugar in your blood. This is of potential interest for individuals with high blood sugar, such as people living with type 2 diabetes. However, how ketone supplements impact metabolism is not fully understood but using high throughput analysis techniques that can characterize hundreds to thousands of metabolites in the blood (known as "metabolomics") may allow researchers to discover novel compounds within the body that are altered by ketone supplements. This will improve our understanding of how ketones impact metabolism and guide future research.

Inclusion Criteria:

• over the age of 18 years
• able to fast overnight

Exclusion Criteria:

• being a competitive endurance athlete
• following a ketogenic diet, low-calorie diet, periodic fasting regimen, or regular consuming ketone supplements
• being unable to travel to and from the university
• being pregnant or planning to become pregnant during the study
• having been diagnosed with a chronic disorder of glucose or fat metabolism, including type 2 diabetes, chronic pancreatitis, or gallbladder disease
• being unable to read or communicate in English

The investigators will share individual patient data (de-identified) with researchers upon request.