Most people begin a new diet to lose weight. Some also want to improve their health. So which diet is more effective at weight loss and improving health, a low-carb or a low-fat diet?
In a research study published in the 2014 Annals of Internal Medicine, scientists looked at the effects of a low-carbohydrate diet — compared to a low-fat diet — on body weight and cardiovascular risk factors. What they found is that the low-carbohydrate diet was better for weight loss and it reduced cardiovascular risk factors.
This is great news for those who follow the principles outlined in Become a Fat-Burning Machine, because it offers more scientific validation for our fat-burning methodology!
Let’s look at more details.
Participants in the Study
The research was a clinical trial conducted at Tulane University School of Public Health and Tropical Medicine in New Orleans. Participants included 148 men and women between the ages of 22 and 75, who were without cardiovascular disease or diabetes and of varied ethnic origin. Researchers measured dietary composition, bodyweight and cardiovascular risk factors at 0, 3, 6 and 12 months.
The low-carb diet group was instructed to maintain an intake of digestible carbohydrates less than 40 grams per day. The low-fat group was instructed to keep their daily intake of fat to less than 30% of total calories and keep carbohydrates at 55%. Neither group was instructed to aim for a daily calorie intake and both groups were encouraged to not change their exercise routine.
Participants did meet with a dietitian in weekly individual counseling sessions for the first 4 weeks, followed by small group session every other week for the next 5 months.
Diet Macronutrients: What They Ate
Over the course of the yearlong study, the low-carb diet group reported the following macronutrient breakdown:
| Month | % Fat | % Protein | % Carbohydrate |
| 0 | 32.5 | 17.3 | 48.1 |
| 3 | 42.7 | 25.6 | 28.9 |
| 6 | 43.4 | 26.3 | 27.5 |
| 12 | 40.7 | 23.6 | 34 |
The low-fat diet group reported:
| Month | % Fat | % Protein | % Carbohydrate |
| 0 | 34.7 | 17.6 | 46 |
| 3 | 27.5 | 19 | 52.9 |
| 6 | 27.9 | 18.3 | 52.4 |
| 12 | 29.8 | 18.6 | 54 |
Results After One Year
At the 12-month mark, the low-carb group reported greater decreases in body weight (about 7.7 pounds more) and a greater decrease in fat mass, than the low-fat group. The low-carb group reported greater increases in HDL cholesterol (the good one) and therefore a better ratio of HDL to total cholesterol. The low-carbohydrate group also reduced their triglyceride levels and had improved CRP (C-Reactive Protein), a marker for inflammation. The improvements in these three blood profile markers are associated with a decrease in cardiovascular risk.
Conclusion
Scientists concluded that a “low-carbohydrate diet resulted in greater weight loss and reduction in cardiovascular risk factors as compared to a low-fat diet among obese adults.”
So, give up the old paradigm that weight loss is best achieved on a low-fat diet. Reduce your percentage of carbs, add in some very modest exercise, and you’ll finally become a Fat-Burning Machine!
