What is the best diet to lose weight?
Researches took a close a look at the effects of three different kinds of diets you get on for maintenance of weight after initial weight loss diet.
They looked at the effect on energy, hormones and components of a condition called the metabolic syndrome which is a name for a group of risk factors that occur together and increase the risk for coronary heart disease, stroke and type 2 diabetes.
The condition usually manifests itself extra weight around the waist- abdominal obesity
The findings were not affected by how much calorie or energy was in the diet of the obese and overweight young adults studied.
This finding is different from the notion that a calorie is a calorie from a metabolic or energy burning point of view as per Dr Ebbeling of the New Balance Obesity Prevention Center, Children’s Hospital Boston
The researchers performed a controlled feeding study.
They used 21 overweight and obese young adults, put them on a low-calorie diet so they lost and then put them on a series of weight-maintenance diets for 4 weeks each.
This is how they did it:
Their first step was to screen 681 men and women aged 18-40 years who were overweight with a body mass index (BMI) of 27 or higher for participation in the study. Of these, 17 men and 15 women were allowed in the study and they agreed to the rigorous dietary restrictions of the study.
The study subjects followed a standard low-calorie diet that restricted energy intake such that they lost weight. Detailed assessments also were done to establish each subject’s energy requirements for stabilizing their weight at this reduced level.
After the subjects achieved a 10%-15% weight reduction, they each consumed one of the three same-calorie diets for 4 weeks, then switched to another of the diets for another 4 weeks, then to the third diet for a final 4 weeks.
Before we talk about the different diets let’s talk about something called a glycemic load.
The glycemic load of a food tells how much eating that food raises blood glucose. It is a similar concept as the glycemic index, except it takes serving sizes into account. Theoretically, if a food has glycemic load of one point, it would raise the blood sugar as much as one gram of glucose.
A diet with a low glycemic load has been linked to a lower risk of heart disease.
A diet which is low in carbohydrates automatically has a low glycemic load.
For example: 2 oz peanuts has a glycemic load of 1 and 1 cup white rice has a glycemic load of 33
In the study,the three diets fed to the subjects were the following: 1) a low-fat diet with a high glycemic load and 20% of energy from protein, which reflected conventional recommendations to reduce fat, increase whole grain products, and include a variety of vegetables and fruits;
2) a low-glycemic-index diet with moderate glycemic load and 20% of energy from protein, which replaced some grain products and starchy vegetables with other vegetables, legumes, and fruits;
3) and a very-low-carbohydrate diet with a low glycemic load and 30% of energy from protein, which was modeled on the Atkins diet.
Body weight did not differ significantly among the three maintenance diets, nor did total physical activity or time spent performing moderate to vigorous-intensity activity. Subjects’ ratings of subjective hunger and well-being did not differ significantly among the diets, and blood pressure levels also did not differ.
Both resting energy expenditure and total energy expenditure decreased with all the diets, but the decrease was significantly greater with the low-fat diet.
In addition, the appetite suppressing hormone-the leptin hormone levels were highest with the low-fat diet. These two findings suggest that people following the low-fat diet would be more likely to regain weight than those following the other diets, Dr. Ebbeling and her colleagues said (JAMA).
In contrast, the very-low-carbohydrate diet had the most favorable effects on these components of the metabolic syndrome and on energy expenditure.
The very-low-carbohydrate diet, however, produced higher C-reactive protein levels and higher cortisol excretion levels than the other diets, both of which signal physiological stress and chronic inflammation. In addition, “higher cortisol levels may promote adiposity-gaining weight, insulin resistance (being prone to diabetes), and cardiovascular disease,” the investigators wrote.
Major Finding: A very-low-carbohydrate diet produced the most favorable effects on components of the metabolic syndrome but also increased serum cortisol and CRP.
This study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases, the National Center for Research Resources, and the New Balance Foundation. No conflicts of interest were reported.
The chief limitation of this study is “the difficulty extrapolating findings from a feeding study to a more natural setting, in which individuals consume self-selected diets. In particular, the very-low-carbohydrate diet involved more severe carbohydrate restriction than would be feasible for many individuals over the long term,” Dr. Ebbeling and her associates said.
This study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases, the National Center for Research Resources, and the New Balance Foundation. No other financial conflicts of interest were reported
The summary of the study suggest that a strategy to reduce glycemic load rather than dietary fat may be advantageous for weight-loss maintenance and cardiovascular disease(CVD) prevention,” they noted.
Also reported by MARY ANN MOON, Ob.Gyn. News Digital Network