A Low-Carbohydrate, Ketogenic Diet versus a Low-Fat Diet To Treat Obesity and Hyperlipidemia: A Randomized, Controlled Trial -- Yancy et al. 140 (10): 769 -- Annals of Internal Medicine

Small study comparing low fat and low carb diets.

Conclusions: Compared with a low-fat diet, a low-carbohydrate diet program had better participant retention and greater weight loss. During active weight loss, serum triglyceride levels decreased more and high-density lipoprotein cholesterol level increased more with the low-carbohydrate diet than with the low-fat diet.

A good study, though the limitations may have had a strong influence on the results:

Limitations: We could not definitively distinguish effects of the low-carbohydrate diet and those of the nutritional supplements provided only to that group. In addition, participants were healthy and were followed for only 24 weeks. These factors limit the generalizability of the study results.

I'm also not a fan of including in the conclusion (specifically completion rates as a result of diet) when there are far too many unnoted factors (wish I could see the whole thing), such as adherance to diet and exercise and full disclosure of dietary regiments. I also believe that post intervention psychological analysis of motivation (through interview or survey) is absolutely necessary (though rarely done) in studies such as this, as it something that could have a rather large impact on adherance and success.

In the end, fat loss in both groups is significant, which of course leads us back to the overall "healthiness" of the two different approaches, for which the jury is still out on.

Hmmm, constipation would seem to indicate lack of fiber / vegetables. Don't all diet ideologies advocate higher consumption of low calorie (= low carb and low fat) vegetables?

"Low fat" in this case would seem to be the orthodox <= 30% of calories from fat with overall calorie restriction, not the super low fat approaches that some advocate. Both diet groups in the study took in about the same calories total, but with more variation among the low carbohydrate group.

I can't fathom how you could get enough fiber with a low carb diet. Most of your fiber comes in higher carb foods

But, given many people's dislike for vegetables, it is certainly possible that the dieters in this study did not eat enough of them.

Flax seed + veggies.

I did a report on the atkins diet, and was actually fortunate enough to get a brief phone interview with a researcher at my university who did one of the premier low fat vs low carb diet studies. I don't have the study with me, but he found that over six months people on low carb diets lost more weight and had lower LDL cholesterol and higher HDL cholesterol than those on a low fat diet. However, after a year he found that these differences no longer existed. The study was done by simply giving one group the Atkins diet book and the other a conventional low fat diet book and telling them to follow it. They also received some intensive training at the start on how to do the diet, and then bi weekly checkups.

That seems to be the general consensus in longitudinal studies and meta-analysis. Which means that once again, it falls back on the general impact on health of the two different diets.

If you only eat 2000 calories you should get about 30 grams of fiber

Is that lettuce? It would take 40 cups of lettuce to get 30 grams of fiber ..or 38 cups of spinach
or 12 cups of broccoli
or 12 cups of cauliflower
or 73 large spears of asparagus

I doubt anyone eating 2000 calories eats those kinds of numbers. What low carb vegetables are higher in fiber?

For me, the highest fiber items I can find are whole grains, sweet potatoes, beans...all high carb

I know for one thing, when people go on restricted low carb diets such as the Anabolic diet, they don't eat any whole grains or breads but use those 30grams of carbs very carefully and only eat brocolli and other veggies.

Veggies + flax seed = enough fiber.

I have read some things that suggest fiber isn't even good for you.

On a keto diet the foods you eat are very low waste foods.

But yeah, just eat some flax seed and some veggies and you get enough fiber.

my digestive system is a lot happier with me when I eat fiber

It takes 1 1/4 cups of flax seed to make 30 grams of fiber, eat up!

I got 97 grams of fiber today LOL I'm definitely not low carb though

Ya I can easily reach 60g per day, and used to be at 90+. Its all about double fiber bread and Mission Wraps.