The phrase "acidity levels" refers to how acidic or basic a substance is. It indicates the concentration of acid in a solution, with higher levels indicating greater acidity and lower levels indicating less acidity. Full definition
The dieting approach Virgin came up with is founded upon the idea that fat storage and the fat burning process of the body are strongly influenced by acidity levels in the body metabolism rate. (findperfectdiet.com)
The researchers then worked the experimental data into a global ocean circulation model to see how multiple species, competing with each other, responded to rising acidity levels. (sciencedaily.com)
And as each part or organ of the body has different acidity levels, the pH will vary also. (paleodietfoodlist.net)