Low glycemic index diet is better for the health: not all calories are created equalBy cwan | September 4th, 2017
Many people experienced weight re-gain after a big weight loss. Research shows that only one in six people could maintain even 10 percent of their weight loss long-term. The phenomena remained to be an enigma until researches showed that weight loss often triggers a dramatic decrease on the rate at which people burn calories (i.e., slower metabolism). This means that, even if you take in the same amount of calories, a slower metabolism will cause weight gain. This helps to explain why people tend to re-gain lost weight.
There are lots of popular diets around. A low-fat diet is traditionally recommended by the U.S. Government and Heart Association. Some people swear by the Atkin’s diet (a low-carb and high fat and protein diet), while others swear by a low-glycemic index diet (a diet rich in whole grain, fruits and vegetables with a balanced ratio of fats and proteins). The question is – which diet best help people to maintain lost weight after dieting?
A study, led by researchers from the Boston Children’s Hospital, noted that each diet has different effects on your metabolic rate and overall systemic heal. 21 adults ranging 18 to 40 participated in the study. Each person first lost10- 15% of his/her body weight. Then, each person completed all three of the following diets in random order, each diet for four weeks at a time. Each of the three diets fell within the normal healthy range of 10 to 35 percent of daily calories from protein.
- A low-fat diet, which reduces dietary fat and emphasizes whole grain products and a variety of fruits and vegetables, composed of 60 percent of daily calories from carbohydrates, 20 percent from fat and 20 percent from protein.
- A low-glycemic index diet, made up of minimally processed grains, vegetables, healthy fats, legumes and fruits, with 40 percent of daily calories from carbohydrates, 40 percent from fat and 20 percent from protein. Low glycemic index carbohydrates digest slowly, helping to keep blood sugar and hormones stable after the meal.
- An Atkins diet (i.e., low-carbohydrate diet), modeled after the Atkins diet, composed of 10 percent of daily calories from carbohydrates, 60 percent from fat and 30 percent from protein.
The results showed that the Atkin’s diet produced the biggest improvements in metabolism, but with a significant negative effect: this diet increased participants’ cortisol and C-reactive protein level. This means that the Atkin’s diet causes systemic inflammation and stress, which could lead to insulin resistance and cardiovascular disease.
In addition, the results showed that the low-glycemic index diet had similar metabolic benefits to the Atkin’s diet but without negative effects of stress and inflammation as seen by participants consuming the Atkin’s diet.
Though a low-fat diet is recommended by the U.S. Government, the study showed that this diet greatly slows down the metabolism and causes an unhealthy lipid pattern and insulin resistance. Specifically, the researcher observed that the total calories burned plummeted by 300 calories on the low fat diet compared to the other two diets. This means that, with the same amount of calorie intake, if you are on a low fat diet, you will need to carry out an hour of moderate-intensity physical activity to compensate for the slower metabolism, while someone on a low glycemic index diet could just sit around and burn same amount of calories as you.
So what’s the take home message? The low glycemic-index is the healthiest diet according to this study.
Thanks for reading.
Dr. Connie Wan
Journal Reference: Cara B. Ebbeling et al. Effects of Dietary Composition on Energy Expenditure During Weight-Loss Maintenance. JAMA, June 27, 2012 DOI: 10.1001/jama.2012.6607