Answer:
1. Tuna (Protein content: 32g per 100g)
2. Breast chicken (Protein content: 31g per 100g)
3. Cheddar (Protein content: 25g per 100g)
4. Walnuts (Protein content: 16g per 100g)
Explanation:
1. Tuna. Tuna is rich in essential amino acids (i.e., lysine, methionine, cysteine, threonine and tryptophan), and omega-3 fatty acids, which helps to prevent cardiovascular diseases. Moreover, this food is an important source of vitamin A, B Group vitamins (i.e., thiamin, riboflavin, niacin) and minerals (i.e., calcium, phosphorus, iron, etc.) (Fatimah <em>et al.</em> 2019).
2. Chicken breast. Chicken breast is low in fat and an excellent source of protein, vitamins (vitamin B6, niacin), and many essential minerals (selenium, phosphorus,iron, calcium). Chicken is a rich source of methionine, the precursor of homocysteine (Bansal and Joshi 2017).
3. Cheddar. Cheddar cheese is produced from milk, which has a good content of calcium that helps to prevent osteoporosis and vitamin K. This food has significant quantities of essential amino acids (e.g., lysine, threonine, and tryptophan) (Gueimonde <em>et al.</em> 2019).
4. Walnuts. Walnuts are rich in fats (lipids), especially omega-3 fatty acids, which are required for normal brain function (Haider, Saida, <em>et al.</em> 2011). Moreover, walnuts have a high content of arginine amino acid.
