Antibodies, also known as immunoglobulins, are proteins produced by B-cells in response to the presence of antigens. They bind to specific antigens, marking them for destruction by other immune cells.

Antigens are molecules or molecular structures, often found on the surface of pathogens, that trigger an immune response. They stimulate the production of antibodies or the activation of immune cells.

Antimicrobial peptides are small, naturally occurring peptides produced by immune cells and epithelial cells to inhibit or ward off pathogens (harmful invading microorganisms) such as bacteria, viruses, and fungi (Bahar & Ren, 2013).

Antioxidants are substances that protect cells from damage caused by free radicals, which are unstable molecules generated during normal metabolic processes. They neutralize free radicals by donating electrons, helping to prevent oxidative stress and associated health issues.

Anxiety is an emotion we experience when we anticipate danger, but that danger has not yet materialized. In such a situation, we experience a sense of uncertainty as we prepare for what might happen, even if the threat is not immediate or we are not even sure what the nature of the threat might be. Sometimes, the threat might not even (objectively) exist.

Appetite is the process of hunger arising from learned associations between various cues for food and their consequences. It is one of the two processes of hunger, with the other being homeostatic hunger.

Appetite regulation is a complex feedback system between the hypothalamus, peripheral organs, and physiological, psychological, and environmental variables controlling energy balance, hunger, and satiety.

Our ability to control and regulate our dietary intake, including when, what, and how much we eat.

The arcuate nucleus is a cluster of neurons located at the base of the hypothalamus. It plays a central role in regulating appetite, metabolism, and energy balance. This nucleus integrates peripheral signals such as leptin, insulin, and ghrelin, and contains two key neuron populations, one that stimulates feeding (e.g., AgRP/NPY neurons) and one that suppresses it (e.g., POMC neurons), making it a key regulator of homeostatic control over food intake.

Associative learning is a psychological process in which an individual forms a connection between two events—such as a stimulus and a response—based on repeated pairings. In the context of eating, this explains how environmental cues (like sights, smells, or routines) become linked with food and can trigger cravings or eating behavior, even in the absence of hunger.