Final answer:
Among the given options, replacing saturated fatty acids with mono/polyunsaturated fatty acids is the best recommendation for lowering high levels of blood lipids, as these fats can improve the LDL:HDL cholesterol ratio and decrease cardiovascular risk.
Step-by-step explanation:
To lower undesirably high levels of blood lipids, it is recommended to limit saturated fatty acid intake to less than 10% of total calories and significantly reduce trans fatty acids intake. Consuming a diet with a high amount of saturated fats and cholesterol can elevate cholesterol levels, thus increasing the risk for cardiovascular diseases.
It is beneficial to replace saturated fatty acids with mono and polyunsaturated fatty acids, including omega-3 fatty acids found in foods like fish and flaxseeds. These unsaturated fats can help to lower LDL ("bad" cholesterol) and elevate HDL ("good" cholesterol), improving overall cardiovascular health. In contrast, consuming large amounts of dietary cholesterol can exacerbate the issue, as not all ingested cholesterol is offset by a reduction in cholesterol biosynthesis in the body.
Eating various fresh fruits, vegetables, whole grains, and choosing lean meats along with monitoring portion sizes can assist in achieving a healthier lipid profile. Regular physical activity also plays a crucial role in maintaining healthy blood lipid levels. Hence, among the options provided, replacing saturated fatty acids with mono/polyunsaturated fatty acids is the suggested recommendation for lowering high levels of blood lipids.