If "modern living" includes modern medicine, then, this statement is true because children nowadays often survive who in older times would not. That is, there are babies born with many conditions that could not be fixed, and the little ones would perish. On the negative side of their survival is the fact that often their condition is genetic and can be passed on. So, as a result, nowadays there is the emergence of debilitating traits that before did not emerge because of the survival rates being lower.
I agree with the others here; as a whole, this statement is probably not true based on the factors already mentioned. For the sake of argument, though, I'll try to make a case in favor of your premise.
If "weak" is defined as something besides physical strength, perhaps we are weak--or at least weaker than our ancestors. They were the intrepid and hardy pioneers and adventurers and explorers. They often died young, often because they just wore out; but they were anything but weak. Life was hard, full of difficult challenges and unavoidable obstacles. While there are still those who seek those kinds of experiences, in general we've become a society which wants things to be easy and obstacle-free.
If "unhealthy" is referring to lifestyle, we are surely unhealthy. While it's true that health clubs and fitness centers and aerobics classes are all over, we're still a people plagued with obesity, heart disease, high cholesterol, diabetes...and the list goes on. We do have the opportunities to be healthy; however, the statistics show overwhelmingly that we are not as healthy as our opportunities should make us. That's because it's still our choice, and we are often weak (as in above paragraph).
"Disease-prone" is a little trickier to deal with, since it's not really a quantifiable term; however, I think a case can be made that this is true. The advancements in technology and everything associated with them have created an environment which poses a multitude of dangers to our health. A doctor recently told my 91-year-old grandmother that women who live long enough will get breast cancer; all men who do the same will inevitably get prostate cancer. The environment we've created, while advanced in so many ways, has also unleashed chemicals and toxins which are impossible to avoid. The good news is that, even though we may be more disease-prone, we also have the medical advancements to counterbalance these problems.
Hope that helps!
I also do not agree with this statement. If anything, I might say that modern living has done just the opposite. Modern living makes it easier to stay healthy and free from diseases.
For example, modern living has made it possible for people to go to health clubs to exercise on the latest exercise equipment that optimizes results quicker. Also, people can join aerobics classes or just about any other class for that matter such as yoga or pilates. Not only is this great for the body but for the mind as well.
Modern living has also extinguished many diseases. Diseases that were prominent years ago, such as small pox, are virtually non-existant now due to the numerous vaccines that are available.
I would probably disagree with the statement. I think that modern living, as it is defined in a very vague way, has actually allowed people to reconfigure their living habits in according to health. For example, people who used to consume the typical morning breakfast of two eggs, plate of hash browns, and a side of bacon or ham every morning are now aware of issues such as obesity, cholesterol, and the dangers of a diet with so much saturated fat. Consumers cannot go to any food product without a listing of "Nutrition Facts" on the side of the box. Even fast food restaurants like McDonald's and Burger King have had to deal with providing a more "healthy" alternative on the menu. This is world wide, as well. I am amazed to see cultures that have engaged in unhealthy practices for decades suddenly now take up healthy routines or simply cut back on food consumption. Cultures that could have cared less, tossed it to fate and said, "If it's written, oh well," are now concerned with diabetes, blood sugar, high blood pressure, and hypertension. This is a result of the modern setting, where technology has allowed individuals to fully understand poor health conditions and what people can do to avoid them. At the same time, it is a condition that inundates consumers with facts about obesity, concerns about diet intake, and suggestion of alternatives. Certainly, there is some validity to the statement because consciousness has always seen people that were "Weak, unhealthy, and disease- prone." Yet, I think that there is a flip side to it and what I am seeing now might just be that.