For a long time we have been told that the best way for us to maintain our weight or lose some is to go low fat and restrict our calorie intake. The calories in, calories out paradigm has been the harsh reality and for many people a source of constant frustration. No matter how hard they try, they can’t seem to make it.
Finally we seem to be finding our way back to a more varied way of looking at our metabolism and understanding what our bodies actually thrive of. It’s not only the calories, it matters what source they have. This is knowledge we’ve had for a long time, but in the well meaning attempt to make us “heart healthy” during the last 40 years, it has been lost. Normal, nutrient dense food (meats and organ meats, good fats etc) that we can easily cook on our own has been put to shame and we’ve been guilted by the medical society for not caring enough about our health. The more the “heart-healthy” advice seem to have been followed, the more sick we seem to get.
More and more evidence, both scientific and experiential, is showing that the human race might be doing better with lowering their carbohydrate intake.
The “Annals of Internal Medicine” recently published this randomized study – “The effects of Low-Carbohydrate and Low-Fat Diets“.
They followed 148 subjects for a year, randomly assigned to a low-carbohydrate or a low-fat group (119/80% completed the intervention). There were overweight, men and women, white and black, in the ages between 22-75. The participants did not have Diabetes or cardiovascular disease at the start of the study.
Both groups were tested for a multiple of markers in the beginning of the study and after 3, 6 and 12 months, at which time two 24-hour dietary recalls (one reflecting a week day and one a weekend day) were also collected.
They were given weekly individual dietary counseling sessions from a dietician for the first 4 weeks, then in small groups every second week for the next 5 months and after that in the groups monthly for the rest of the year.
They also got shopping lists, recipes, sample menus for a week, meal planners and guides on how to count macro-nutrients and read nutrition labels, as well as a low-carb/low-fat meal replacement a’ day throughout the study.
The low-carbohydrate group was instructed to eat a diet with less than 40 g of digestible carbohydrates/daily.
The low-fat group was told to have less than 30 % of their food intake from fat (less than 7 % from saturated fat) and about 55 % carbohydrates.
The low-fat diet follows the National Cholesterol Education Program Guidelines.
There was no specific calorie or energy goal, but the participants were instructed not to change their physical activity levels during the study. Both groups received the same information on dietary fiber (25 g/day) and dietary fats (including education on the different kinds of fats and emphasis on benefits of monounsaturated fats and avoiding trans fats).
After a year the participants in the low-carbohydrate group had significantly reduced in weight and fat mass and had also increased their levels of HDL-cholesterol compared to the low-fat group. The levels of triglycerides changed significantly in both groups, the change being bigger for the participants in the low-carbohydrate one.
The low-carbohydrate group also had lower CRP levels (an indicator of overall inflammation) and the estimated 10-year risk for cardiovascular disease (Framingham risk score) than in the low-fat group.
The levels of LDL-cholesterol or blood glucose and the blood pressure didn’t change significantly in any of the groups.
It seems that a low-carbohydrate diet is beneficial for weight loss, especially since people following this diet tend to lose mostly fat mass.
The cholesterol levels have been the main worry for the medical collective when discussing LCHF and other low-carbohydrate diets and this study actually showed beneficial effects on markers for cardiovascular health, especially improving the total cholesterol – HDL-cholesterol ratio.
That should make your doctor/internist/cardiologist happy.
The average low-carbohydrate diet usually aims for 20 % or less of the daily intake to be from carbohydrates, and in this diet the average intake landed on 30% over the year. So of course, we can’t extrapolate the numbers from the study to diets with lower carbohydrate content.
My personal experience in both personal and clinical life does gravitate towards that a the lower the carbohydrate (especially the refined, processed ones) intake, the better.
But if you can experience health benefits like the ones described in the study and not going to extremes, that is good news for us all.
In this study they did their best to keep the activity-level the same, to be able to asses the changes more correctly.
The best way of losing weight and keeping healthy is of course to combine dietary changes with being more active, especially in daily life.
I’m sure that there are more interesting studies to come on this subject, especially since the researchers and the medical society has become aware of the possible benefits of a low carbohydrate diet and need to keep up with the changes that people make themselves in their lives as they start reaping the benefits. Read more of how you can start today here!
What an exciting future!
To the abstract: http://annals.org/article.aspx?articleid=1900694