Everything starts to go south in our 40s, says a local fitness trainer. "Your body starts deteriorating when you hit your 40s," said John Allen, who owns John Allen's Body Sculpturing, 1065 W. Queen Creek Road, and was once rated as one of the Top 10 trainers in the country by Good Morning America. "This is when the metabolism slows down and the body doesn't digest food as fast as it once did. It gets worse if you don't exercise." Doctors say the physical equivalent of the perfect storm hits the body by the time a person reaches their 40s. The body doesn't burn calories as fast as it once did because the metabolic rate decreases about 4 percent each decade. By the time the 40s roll around, it's simply harder to lose weight and keep it off. Many people are forced to watch their diet because the percentage of lean muscle tissue and bone density has decreased but body fat has increased. However, there are remedies to stave off the aging process. "The key to looking younger is to exercise, no and's, if's or but's," Allen said, adding that can be achieved through three simple steps: strength training, cardiovascular activity and proper nutrition. By a person's mid-40s, the body starts to lose about one-fourth-a-pound of muscle every year and fat takes its place. Allen said that is when men start getting love handles and women's hips and glutes start to expand. However, by incorporating strength training exercises, the body can keep from losing this muscle and regain muscle mass. Lifting weights for about 45 minutes to an hour three times a week can provide substantial benefits such as keeping diabetes at bay, Allen said. Cardiovascular activity such as running, aerobic exercise, elliptical machine, treadmill or walking several times a week is a great form of exercise and increases endurance and flexibility. It can also reduce the risk of diabetes, depression and aging of the skin. Keeping a high-fiber, low-fat diet is a key component in maintaining a healthy body. Allen said a steady diet of fruits as well as whole grains helps feed the body vitamins and nutrients it needs. About 30 to 35 percent of your calories per day should come from protein, Allen said. "Carbs just turn into fat in your 40s and should be avoided," Allen warned, adding that carbohydrates should come from foods such as wild rice, oatmeal, wheat or whole grain bread. Exercise is also vital to a person's mental health, claims a new study by the University of Warwick and Dartmouth. The study, which collected data analysis from two-million people from 80 different countries, found 44 is the age at which humans are most vulnerable to depression.