What is the life expectancy of a 400 lb man? let's say a 25 year old 400 lb man with diabetes. how long would he live?

Sorry, mate, seeing the future is not in anyone's job description. However what I can say is that anything could happen, you could live many more years. What I'd recommend to enjoy those years is to eat healthy, live life, and exercise.

The average resting heart rate (hrrest) for a 34 year old is 73 beats per minute2. 34 year old males average heart rates of 71 bpm while females average slightly higher at 76 bpm2. the normal resting heart rate range for all adults and children 10 and over is between 60 and 100 beats per minute3. 90% of 34 year olds resting pulses fall within the range of 54 to 92 bpm. in general, an adult's resting heart rate will be lower for those in better athletic condition.