In Search of a Perfect Diet
For decades researchers knew that losing weight is not as simple as "energy in equals energy out." There are many factors that influences weight balance : biochemical and physiological elements, psychological responses, and lifestyle activities such as exercise, and sleep.
Why It's Difficult to Keep Weight OffPeople who have successfully lost weight have also regained weight, causing much frustration. Dr. Robert Eckel, Obesity expert at University of Colorado's Obesity Clinic and president of the American Heart Association says: "It's difficult for the body to accept being thinner than what it was. Once you have put on extra fat you tend to defend it. If you shed a few pounds, a number of biological and psychological mechanisms help return your weight to where it was."
Some of those factors include:
- food cravings. Dr. Eckel says: " We have reasonably sound evidence that alter people who have lost weight. Their preference for high-fat and high-sugar food goes up. Both make you likely to eat more than you should."
- slower metabolism. To your body, weight loss means starving, impending famine, and death. To preserve life (keep the heart, brain, liver, lungs, etc.going) the remaining fatty tissues must be conserved. "Your basal metabolic rate falls with weight loss, so the laws of physics are working against you. With weight reduction, people lose not just fat, but also a little bit of liver, heart muscle, and other lean tissues," says Dr. Eckel. To stimulate sluggish metabolism, exercise.
- body enzymes work double time to replace lost fat. Lipoprotein lipase (LPL), an enzyme that promotes fat storage is activated during weight loss/fasting. However, you won't actually gain weight unless you eat more food.
- less fat and more carbohydrates burned. The body burns carbohydrates, fats, and proteins (as a last resort) for fuel. After losing weight, glucose oxidation goes up and fat metabolism goes down.
What You Can Do to Keep Weight Off
There are no magic food(s), pills, or shortcuts that will do the trick. Weight balance is a highly individualized phenomenon. However, there are a few strategies that you can employ to help you lose weight:
- Reduce your total fat intake. Monounsaturated fats such as olive oil, avocados, canola oil, etc. may be "healthy" but they're still calorie-rich. They have the same calorie per gram as saturated fats and trans fats. One teaspoon of olive oil, butter, or fish oil have 45 calories.
- Eat more fruits and vegetables with high-fiber and water content. The insoluble fiber will give your meals "bulk" that will keep hunger at bay.
- Reduce your intake of food products made with refined flour, sugar and bakery products made with whole grains. Sure, whole-wheat bread has dietary fiber, but it's not spinach or lettuce. A slice of whole-wheat bread has about 90 to 110 calories compared to 40 calories for a half cup of spinach.
- Eat enough proteins to prevent muscle loss. The Institute of Medicine recommends that healthy adults consume 0.8 grams of protein per kilogram of body weight per day. That's about 25% of total calories. For example; a 1500 calorie diet would contain about 94 grams of protein.
- Avoid or reduce your intake of sugar-sweetened beverages.
- Avoid alcohol intake.
- Exercise. Health Canada recommends that healthy persons engage in daily physical activities for about 60 minutes. Include strength training in your workout. The muscles you build will burn more calories even while your asleep.
- Get sufficient sleep. Sleep deprivation increases appetite by lowering leptin and raising ghrelin levels. Leptin is a hormone released by fat cells. It tells the brain for you to stop eating. Ghrelin is a hormone that triggers appetite. When leptin levels drop,metabolic rate goes down. Inadequate sleep makes insulin less effective. Twenty-year olds who allowed to sleep for four hours only for six nights showed near diabetic status.
Many people lose weight and keep weight off for years. However, maintaining the trimmer you long-term is not as easy as it sounds.
Eckel RH "The Dietary Approach to Obesity: Is it the Diet or the Disorder?" JAMA 2005;293:96-97
Rastrallo MB et al. "Predictions of weight gain in a Mediterranean cohort: TheSegrmiento Universidad de Navarra Study" Am J Clin Nutr. 2006;83:362-370
Speigel K et al. "Brief Communications: Sleep Curtailment in Healthy Young Men is Associated with Reduced Leptin levels, elevated Ghrelin levels, and Increased Hunger and Appetite" Ann Intern Med 2004;141(11):846-850