Fresh air and sunshine
Try and be outside for an hour or more a day, the best time is between 11am and 12 noon if it's not summer and not too hot.
As a minimum you should be exercising for half an hour a day, 6 days a week. An hour a day is much better. If you make it fun you will be more likely to continue. Don't do the same thing every day, vary your workout. Or find a friend to keep you accountable. Exercise is great, but exercising outside is even better.
Walk as much as you can
Don't park your car close to your office, park it at the other end of the parking lot and walk further. For local trips, consider walking instead of driving.
If you don't want to digest pesticides consider moving to organic foods. If cost is an issue, consider eating half your foods organic, which will at least be some improvement to your diet.
Drink plenty of clean, filtered water
Reverse osmosis is the best type of filtered water. Consider getting a reverse osmosis water filter system fitted in your home.
Eat less red meat and more fish
Vegetables are better than meat and white meat is better than red meat. Try and consume red meat once a week or less. Fish is better than meat, try and consume fish at least twice a week.
Cook your own meals
The producers of pre-packed ready meals are not interested in your health, they are interested in their profit. They add things to the meals that you would never add if you cooked the meal at home. Whenever possible cook your own meal at home rather than buying a pre-prepared meal.
One clove of garlic finely chopped and swallowed with a glass of water every day will have an amazing improvement to your health. Some people say it prevents cancer.
Reduce your sugar, but don't replace sugar with anything else
Sugar is bad for you in many ways, but all the alternatives are even worse. Try and cut out the need to eat food and drink beverages sweet. You can get used to eating things not sweetened. Reduce the sugar bit by bit and then cut it out completely. If you need something sweet, eat fruit.
Limit your calories
Under eat at every meal and every day. Stop your meal before you are full. If you have that full feeling, you've eaten too much. Overeaters don't live to be 100.
Eat nuts in small quantities
Nuts are high in unsaturated fats, fiber and micronutrients, and are action packed with goodness. But we eat them in quantities that are too large. Half a handful of mixed (unsalted) nuts a day would be perfect to improve your health, and make sure there is a Brazil Nut in your hand when you consume them.
Have a support network or join a church
People need to be in community and not in isolation. It has been reported that people who belong to a church live longer. Maybe it's because they tend not to drink or smoke, or maybe it's because of the support network.
Stimulate your brain
Keeping your brain alert keeps your body alert and healthy. Do brain exercises or crossword puzzles every day. Challenge your brain and don't let it vegetate.
Get the right amount of sleep
Go to bed early enough to get enough sleep, but oversleeping can be unhealthy too. Try to go to bed and get up at the same time every day.
"A cheerful heart is good medicine" Proverbs 17:22
Reduce your stress
Stress causes multiple health problems. Try reducing the stress in your life, practice relaxation techniques.
Smoking increases the rate at which you age. Do you know any smokers who made it to 100?
Don't eat corn products or high fructose corn syrup
Most corn is genetically modified and covered with a lot of pesticides. High fructose corn syrup should not be consumed by humans and is the number one source of calories in this country. There are many dangers of consuming high fructose corn syrup, but really all corn products should be avoided.
Live where there's less air pollution, live close to nature
We can't all choose where we live, but if we can, we should choose to live where the air pollution is less and the air is healthier.
This is a good start
There is much more you can do to improve your longevity.
This is not medical advice. If you have a medical problem, go and see a doctor.