Some cooking methods have always been associated with denaturing nutrients within the food we eat and as such may not be as nutritious as others.
So where did this notion come from?
This idea stems from two main factors: heat and water. Higher cooking temperatures are claimed to break down and even destroys certain vitamins such as Vitamin C. Some vitamins are actually water soluble and as such, larger volumes of cooking water are claimed to cause these vitamins to leach out and be lost in the cooking process.
There seems to be some truth in this claim. However, a bias may present itself in this since the cited studies only examine just one or two specific vegetable species and thus do not give a fair representation on foods as a whole. Furthermore, these studies only test just one or two cooking methods and as such it is difficult to get a good bearing on the effect of cooking on the food’s nutritional value.
These studies conclude that one cooking method is superior to the other but forming general conclusions from these findings can be misleading; this carries the assumption that the same vitamin will behave in the same way in all the other different vegetables.
This assumption was highlighted in a 2015 research paper in the LWT – Food Science and Technology Journal by Sylvie Bureau and others (Are folates, carotenoids and vitamin C affected by cooking?). The researchers analysed the effect of boiling, steaming, pressure steaming and microwave cooking on vitamins on 13 different frozen vegetables to determine the best method of cooking. Interestingly, the best method was dependent on which nutrient one was looking at as well as which vegetable one was cooking. For example, the study found that in spinach branches, carotenoids were preserved best when steaming was used in cooking. However, with hashed spinach, pressure cooking preserved more carotenoids than steaming.
Also, a lot of individuals are wary of the effect that microwaving has on the nutritional value of the food they consume. A Science – Based Medicine research article done in 2014 by Steven Novella concluded that microwave cooking is a safe technology that has a positive net effect on food nutrition. This does not imply that microwaving is the best cooking method but certainly can lay to rest any unease about using microwaving as a form of cooking sometimes.
The most common finding among scientific literature was that boiling seems to do the most damage to nutrients. This is probably because boiling combines high temperatures and large amounts of water. Thus, in the study mentioned by (by Sylvie Bureau) actually found that boiling preserved the least amount of vitamin C across all 13 frozen vegetables. Consequently, due to the lack of general consistent results across all vegetables and cooking methods (save for boiling which was consistently the worst), it is difficult for one to give a simple recommendation on which method best preserves the nutritional quality of the frozen vegetables.
On average, the steaming method seems to do slightly better in cooking whereas boiling may be slightly worse; the difference in nutrient preservation in steaming is not enough to consider steaming as the best method of cooking. In conclusion, the idea that some methods are absolutely better than others when it comes to cooking and especially regarding vegetables is false.
The perfect solution would be to cook different vegetables in different manners so as to maximise on nutrient preservation within these vegetables. Since this is not practical then the best method would be to include a variety of cooking methods in food preparation as well as including different fruits and vegetables within one’s diet. Furthermore, bodybuilders as well as athletes may want to include supplements within their diets. Supplements are substances that isolate nutrients in smaller portions giving the users concentrated doses of nutrients and thus delivering on nutrients that one could not possibly acquire through their diet. A good example of a supplement would be Gold Standard Whey: a supplement that offers concentrated amounts of protein to the athletes. This helps as the amount of protein a normal bodybuilder would require could not possibly be obtained comfortably within their daily diet.