AT THIS time of year many of us resolve to prioritize our health. So, it is no surprise there’s a roaring trade of products purporting to guarantee you live longer, be healthier and look more youthful.

While an estimated 25% of longevity is determined by our genes, the rest is determined by what we do, day to day.

There are no quick fixes or short cuts to living longer and healthier lives, but the science is clear on the key principles. Here are five things you can do to extend your lifespan and improve your health.

1. Eat a predominantly plant-based diet

What you eat has a huge impact on your health. The evidence overwhelmingly shows eating a diet high in plant-based foods is associated with health and longevity.

If you eat more plant-based foods and less meat, processed foods, sugar, and salt, you reduce your risk of a range of illnesses that shorten our lives, including heart disease and cancer.

Plant-based foods are rich in nutrients, phytochemicals, antioxidants, and fiber. They’re also anti-inflammatory. All of this protects against damage to our cells as we age, which helps prevent disease.

No particular diet is right for everyone but one of the most studied and healthiest is the Mediterranean diet. It’s based on the eating patterns of people who live in countries around the Mediterranean Sea and emphases vegetables, fruits, wholegrains, legumes, nuts and seeds, fish and seafood, and olive oil.

2. Aim for a healthy weight

Another important way you can be healthier is to try and achieve a healthy weight, as obesity increases the risk of a number of health problems that shorten our lives.

Obesity puts strain on all of our body systems and has a whole myriad of physiological effects including causing inflammation and hormonal disturbances. These increase your chances of a number of diseases, including heart disease, stroke, high blood pressure, diabetes and a number of cancers.

In addition to affecting us physically, obesity is also associated with poorer psychological health. It’s linked to depression, low self-esteem, and stress.

One of the biggest challenges we face in the developed world is that we live in an environment that promotes obesity. The ubiquitous marketing and the easy availability of high-calorie foods our bodies are hard-wired to crave mean it’s easy to consume too many calories.

3. Exercise regularly

We all know that exercise is good for us — the most common resolution we make this time of year is to do more exercise and to get fitter. Regular exercise protects against chronic illness, lowers your stress, and improves your mental health.

While one of the ways exercising helps you is by supporting you to control your weight and lowering your body fat levels, the effects are broader and include improving your glucose (blood sugar) use, lowering your blood pressure, reducing inflammation, and improving blood flow and heart function.

While it’s easy to get caught up in all of the hype about different exercise strategies, the evidence suggests that any way you can include physical activity in your day has health benefits. You don’t have to run marathons or go to the gym for hours every day. Build movement into your day in any way that you can and do things that you enjoy.

4. Don’t smoke

If you want to be healthier and live longer then don’t smoke or vape.

Smoking cigarettes affects almost every organ in the body and is associated with both a shorter and lower quality of life. There is no safe level of smoking — every cigarette increases your chances of developing a range of cancers, heart disease, and diabetes.

Even if you have been smoking for years, by giving up smoking at any age you can experience health benefits almost immediately, and you can reverse many of the harmful effects of smoking.

If you’re thinking of switching to vapes as a healthy long-term option, think again. The long-term health effects of vaping are not fully understood and they come with their own health risks.

5. Prioritize social connection

When we talk about living healthier and longer, we tend to focus on what we do to our physical bodies. But one of the most important discoveries over the past decade has been the recognition of the importance of spiritual and psychological health.

People who are lonely and socially isolated have a much higher risk of dying early and are more likely to suffer from heart disease, stroke, dementia, as well as anxiety and depression.

Although we don’t fully understand the mechanisms, it’s likely due to both behavioral and biological factors. While people who are more socially connected are more likely to engage in healthy behaviors, there also seems to be a more direct physiological effect of loneliness on the body.

So if you want to be healthier and live longer, build and maintain your connections to others.

Hassan Vally is an associate professor in Epidemiology at Deakin University.