Leslie, your book starts by examining the habits of people who live healthfully to 100. What habits do they have in common?

As much as 80 per cent of how well you will age is determined by your habits, not your genes. Scientists have studies the world's 5 longevity hot spots -- called Blue Zones -- to determine what habits help these people live exceptionally long and healthy lives. In fact, Blue Zone residents are 10 times more likely to reach 100 than are North Americans. These communities include Sardinia (Italy), Okinawa (Japan), Loma Linda (California), Nicoya Peninsula (Costa Rica) and the Greek Island of Icaria.

Despite the fact these communities are separated by thousands of kilometres and different cultures, they share a number of habits which undoubtedly contributes to their longevity.

  • They follow a plant based diet and eat little or no red meat
  • Alcohol is consumed moderately or not at all
  • Overeating is uncommon; Blue Zone residents appear to eat only enough calories to stay lean
  • Exercise is a daily part of life – usually walking built in to daily life
  • Each community has a strong sense of purpose and spirituality which bonds residents together.

2. You also give six habits for successful longevity -- what are they?

Based on research from Blue Zone residents and large studies conducted around the world, there are six lifestyle habits that are associated with a longer life expectancy:

  • 1. Eat a plant based diet -- it's full of antioxidants, phytochemicals that help fight aging in cells
  • 2. Get regular exercise -- helps you live longer not only by reducing disease risk but also by combating the natural age-related changes that happen to your muscles, bones and joints.
  • 3. Exercise your brain -- to maintain your "cognitive reserve" which is your brains ability to preserve memory and fight off damage caused by Alzheimer's.
  • 4. Get proper sleep -- seven to nine hours per night; too little -- and too much -- sleep has been linked with a shorter life expectancy in many studies. Too little sleep raises blood pressure, impairs blood sugar control, increases stress hormones and increase inflammation in the body.
  • 5. Maintain a positive attitude -- optimism has been associated with a longer life in many studies. Having a positive attitude actually affects the body's chemistry.
  • 6. Stay connected to others -- the social networks you develop in life play a role in how long you'll live. More social contact with friends, relatives and the community predicts a longer, active life.

3. Okay, so how should you change your diet to delay aging and promote longevity?

Increase antioxidants. It's widely thought that damage to cells caused by free radicals accumulates over time and contributes to aging and many age-related diseases. Antioxidants like vitamins C and E, beta-carotene, selenium and countless natural compounds found in plant foods combat harmful free radicals.

The best sources of antioxidants are fruit and vegetables; aim for seven to 10 servings (combined) each day. According to research that measured the antioxidant power of foods, top scoring fruit include prunes, raisins, berries, plums, oranges, red grapes and cherries.

Kale, spinach, Brussels sprouts, broccoli, beets, red peppers, onions and eggplant are among the top ranked vegetables.

Choose low GI carbs. Refined grains and sugary foods -- called high glycemic index (GI) foods -- are digested quickly and cause a rapid rise in blood sugar and insulin, the hormone that moves sugar into cells.

Scientists believe that maintaining low levels of insulin in the blood can help pave the way to a long and healthy life by affecting proteins in cells associated with longevity. Foods with a low glycemic index (GI) release their sugar gradually into the bloodstream and don't produce a rush in insulin.

Low GI foods include 100 per cent stone ground bread, steel-cut oats, 100 per cent bran cereal, brown rice, sweet potatoes, pasta, apples, citrus fruit, pears, grapes, legumes, nuts, milk and yogurt.

Eat more anti-inflammatory foods. Chronic inflammation -- the ongoing release of inflammatory chemicals in the body -- is recognized as a major determinant of many age-related diseases.

Omega-3 fats, monounsaturated fat and phytochemicals called flavonoids are compounds in foods that help fight inflammation.

Anti-inflammatory foods include salmon, trout, sardines, olive oil, avocado, almonds, berries, apples, onions, dark chocolate, soybeans, red grapes and green and black tea.

Reduce calories. Calorie restriction (CR) -- eating fewer calories while getting all the protein, vitamins and minerals needed for good health -- has been shown to extend lifespan in every species tested so far. On a lower calorie diet animals live up to 30 per cent longer and remain more youthful, energetic and healthy than animals fed their usual diet.

Cutting calories has been shown to reduce free radical production and inflammation in the body and stimulate special genes that turn off age-promoting activities in cells.

A 25 per cent calorie-restricted, nutrient-rich diet is currently being investigated in 200 U.S. adults; results are expected in 2012. Participants are eating 25 per cent fewer calories than required to maintain their current body weight.

To help you cut calories safely, I recommend that people consult a registered dietitian.

4. You also include a diet in the book for people to follow. Will it also help people lose weight in 2011?

Yes, it will. The diet plan is based on a calorie cut of 25 per cent of what's required to maintain a person's current weight. Weight loss is definitely a side effect, but it is not the main purpose. The plan is based in the concept of calorie restriction -- eating a lower calorie, nutrient rich diet that can forestall aging in the body.