The specific aim of this study is to determine molecular pathways that differentiate metabolically healthy vs unhealthy human phenotypes, and to investigate the therapeutic potential of pro-resolving lipids. Investigators will recruit volunteers that are metabolically healthy or unhealthy that fall within three BMI ranges: lean (18.-24.9 kg/m2), overweight (25.0-29.9 kg/m2) and obese (>30.0 kg/m2). Investigators hypothesize that metabolically healthy individuals have a superior endogenous capacity to regulate an inflammatory/resolving response.

Inclusion Criteria:

• Informed signed consent has been obtained from the volunteer.
• The volunteer has a BMI greater than 18.5 kg/m2
• Men and women over the age of 18 are included.

Exclusion Criteria:

• The study staff contacting a potential participant perceives that the individual has difficulty understanding the information.
• An MD determines that the individual is on too many medications to participate.
• The individual takes a medication that is approved by the MD, but he/she is not willing or not able to wait with any potential morning medication until after their fasted blood-draw.
• The individual states that they have increased bleeding tendency or are using anti-coagulant (blood thinning) medication.
• The individual has some form of chronic inflammation.
• The individual regularly uses medication that affects inflammatory resolution (e.g., low-dose aspirin).
• The individual uses immunosuppressive drugs (e.g., methotrexate).
• The individual regularly consumes fish oils (omega 3).
• The individual has significant gastrointestinal problems.
• The individual smokes or uses chewing tobacco.
• The individual has been drinking alcohol two days before the study visit.
• The individual has tattoos or body piercings on the forearms and / or the stomach that can affect the examination.
• The individual does not follow instructions given in the research study.

Individuals that contact the investigators (via phone or email) and express an interest in participating in the study will be invited to an information visit, after which the individual has at least 24 hours to consider their participation. For those that are interested in the study, the investigators then proceed to schedule visit 1-5.