Fats

Fats (also known as 'lipids') are – like proteins and carbohydrates – macro nutrients and serve our bodies as energy and carbon sources.

Every single one of our cells is encapsulated with a flexible double layer of lipids. Without these fats our cells wouldn't even exist as such (Alberts et al. 2015b). Most fats our bodies can synthesise from other carbon sources (i. e. macro nutrients). There are, however, two classes of fatty acids, which we need to absorb directly from our food – the so-called omega-3 and omega-6 fatty acids (Spector and Kim 2015). So, just as there are essential amino acids there are also essential fatty acids.

Since fats do serve as carbon sources, we can synthesise what sugars we need – for example for the upkeep of our blood sugar or for protein modification – from fats. There exists only one healthy cell type, which can exclusively use sugar as fuel – our red blood cells (Alberts et al. 2015a, Kelra et al. 2024, Chatzinikolaou et al. 2024). Contrary to popular wisdom, most of our cells don't need sugar for energy production (ATP–ADP gradient upkeep). Most metabolic ailments are even caused by excessive sugar- and carbohydrate consumption. The problems with a carbohydrate-based metabolism will have to wait for another article.

In our food, we find fats both in animal and plant products. In plants, we primarily find them in kernels, nuts, and legumes. In animals, we find fats in all tissues.

The superiority of fats over carbohydrates as energy and carbon sources, too, will have to wait for another article, as it would make this one unreasonably long and dense.

Alberts, B., Johnson, A., Lewis, J., Morgan, D., Raff, M., Roberts, K., and Walter, P. (2015). Cell Chemistry and Bioenergetics. In Molecular Biology of the Cell, (Garland Science, Taylor & Francis Group, LLC), pp. 43-108.

Alberts, B., Johnson, A., Lewis, J., Morgan, D., Raff, M., Roberts, K., and Walter, P. (2015). Membrane Structure. In Molecular Biology of the Cell, (Garland Science, Taylor & Francis Group, LLC), pp. 565-596.

Chatzinikolaou, P.N., Margaritelis, N.V., Paschalis, V., Theodorou, A.A., Vrabas, I.S., Kyparos, A., D’Alessandro, A., and Nikolaidis, M.G. (2024). Erythrocyte metabolism. Acta Physiologica 240.

Kalra A, Yetiskul E, Wehrle CJ, et al. Physiology, Liver. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK535438/, accessed on 14/10-2024 at 1718 h CEST.

Spector, A.A., and Kim, H.-Y. (2015). Discovery of essential fatty acids. Journal of Lipid Research 56, 11-21. 10.1194/jlr.R055095.