When we talk about the issue about health, we usually think of cooking, since human firstly understood how to used fire, cooking had been tight with us for thousand and thousand of years, yet, according to the status quo, people in the future may cook less and less than before. let me state the reasons.
First of all, over 500 years recently the living standard have been increased very rapidly with the less and less free time, If we are the barberian in the ancient time, we may only need to worked for 2 hours or 3 hours per day, so we had much of time to think how we could made today meal delicious, But for nowadays, a person who at least should work almost 8 or 9 hours per day, except sleeping and entertaining, the time we left for cooking is too few to mention, and that is the main reason why we get a new service called food delivery.
The second reason is in modern society human are intent to make their body shape attractive or we can say body fit, people think healthy diet are more and more important in nowadays, so many people in order to keep fit they would rather starving, that is a pretty odd perspective, yet, many people did that, For instance one of my close friend who was crazy on keeping fit. she only eat two meals per day, Indeed it makes her body very very thin, however she sick a lot, and often get tried while she was doing stuff,  the reason is pretty obvious that she did not gain energy from foods, what confuse me that this style has been more and more popular in young peoples rather than doing some exercises, so this kind of trend of rejecting foods will also cause people to spend less time to cook.
Here someone has to say that "even though human don`t need to cooking, human will still cooking because it has became to our part of culture." Indeed, it is true, as long as human survive, human will never stop cooking, yet the reality is that there are less and less time to do so, though they are willing to cook but without time, we can not do any things, plus we don`t have that much time to eat. why human want to invent instant noodle, because human don`t have enough time to cook, also because cooking is not that convinient as human thought.
So, all in all with the technology developed we probably will have artificial intelligence to cook for us, or with the popularity of food delivery human will more and more frequent to use that service. Not matter what will future like  
the thing we can make sure that human will spend less time to cook than we used to be.