Don't leave the table stuffed to the gillsReducing calorie intake is healthy, and not just for keeping your weight down. Energy needs to be burned in Professor Carl Johan Östgrenthe cells and during this process oxygen radicals are formed. These are aggressive substances that create oxidative stress which, among other things, contributes to causing cancer and cardiovascular disease.
"Undereating slightly in the form of limited calorie intake is probably beneficial in the long run. We are constructed to be able to take periods of shortage of food," says Carl-Johan Östgren, professor of General Medicine.
The daily calorie requirement is governed by many factors such as age, gender, physical activity and body weight. If we want to take it right down, then roughly speaking 1,500 kilocalories per day is sufficient for women and 1,800 for men, assuming they are reasonably physically active. However, there is a risk if the diet is too limited in variety – getting the necessary minerals, vitamins and proteins is especially important when following a low calorie diet.
It is, however, not possible to ethically conduct randomised long-term studies on the significance of diet. We go to the epidemiological data. We know that people in various places in the world – Okinawa in Japan, for example – who eat a low energy diet can live to very old ages.
Humans have a mechanism in the brain that regulates the appetite. If this was 100 % precise the individual would maintain an even weight, but if it goes off by even one percent it puts on/takes off 2 kg per year. In a society with a surplus of food, that can easily mean 10-12 kg over one decade.
Avoid being overweightExcess weight and obesity are in themselves threats to a long healthy life. BMI is a blunt tool. Abdominal height gives a better measure. It should be measured lying down. Abdominal fat that does not "flow out" but rather describes an upward outward curve is layered among the organs and has a major impact on the metabolism, which means a risk of things such as insulin resistance and type 2 diabetes. The ideal waist measurement that gives the lowest risk of cardiovascular disease is below 80 cm for women and 94 for men.
"We should try and keep the weight we had as 20-year-olds all our lives. That’s what happens with indigenous peoples," Östgren says.
One American study predicts that if the current trend of obesity in the United States continues, it will cancel out the positive health effects of reduced smoking.
Choose a healthy dietA healthy meal“Mediterranean diet” refers to the food on Crete in the 1950s. That means vegetables, nuts, grains, olive oil, fish, shellfish and a daily, moderate intake of wine, but with only small amounts of red meat.
In the well-known Lyon Heart Study, 605 people who had survived their first heart attack took part. Half were randomly allocated to a group who lived on Mediterranean food, while the others ate a normal though moderate diet. The study was stopped early since the positive effects of the Mediterranean diet were so obvious. According to other studies, this is because the diet provides a large amount of monounsaturated and saturated fatty acids, but low intake of trans fats, a lot of dietary fibre, antioxidants, polyphenols and magnesium – all positive for good health.
Keep movingRegular physical activity, such as brisk walks of at least 40-50 minutes each day and sitting still as little as possible counteracts both cardiovascular disease and various forms of cancer. Movement also helps prevent osteoporosis and alleviates the symptoms of menopause.
“Sitting still for long periods is just as dangerous as not moving at all,” says Mats Hammar, professor of Obstetrics and Gynaecology.
The effects of physical activity on heart and vascular disease appear mostly due to the fact that it lowers blood pressure, while the effect on blood lipids is more open to debate.
A meta-study based on 250 epidemiological studies provides convincing evidence that physical activity reduces the risk of breast and intestinal cancer, and probably also lung and prostate cancer as well.
One simple way of keeping track of our physical activity is to wear a pedometer. A healthy adult should be taking more than 10,000 steps per day, the equivalent of walking six to seven kilometres. Less than 5,000 steps is seen as a “sedentary” life style.
Working out regularly has a major impact on health. Most surveys show a more than 50 % reduction in mortality among very fit people compared with those with a sedentary lifestyle. Working out has also been shown to have positive effects on psychic well-being, partly because it improves the quality of sleep among middle-aged and older people with sleep problems.
Take some tried and tested pills
Vitamin D deficiency lies behind a number of different illnesses. Most well known of these is rickets, known in Sweden and elsewhere as “the English disease”, which causes a softening of the skeleton and may affect children between two and three years old. The vitamin is important for things such as absorption of calcium and phosphate, and protects against osteoporosis and inflammatory processes. Vitamins D2 and D3 occur in foods like fish and eggs. Vitamin D3 is formed in the skin under ultraviolet light. Sunbathe in moderation and eat fish!
Selenium occurs naturally in the earth and is enriched in crops, but it is geographically very unevenly distributed. In the region of Karelia where selenium is scarce, the occurrence of cardiovascular disease is unusually high. In a well-known study by researchers at Linköping University and the Karolinska Institute, it was shown how a dietary supplement of antioxidant Q10 and selenium can halve the risk of dying from cardiovascular disease. Both substances combat oxidative stress, which is characteristic of patients with heart failure. But both of these substances were necessary for a good clinical effect.
About 10-15 % of older adults have a deficiency of vitamin B12. This is associated with neurological diseases and diseases of the blood.
What the research says
Behind the professors’ article lies a broad review of the latest research on the significance of lifestyle factors in maintaining optimal cognitive, psychological and physical health up through old age.
Article: “Healthy aging and age-adjusted nutrition and physical fitness” by Mats Hammar and Carl Johan Östgren. Best Practice & Research Clinical Obstetrics and Gynaecology (2013)