Thursday, June 30, 2005

Is a Low-Fat Diet Better Long-term?

Only if you're willing to keep your calories restricted - to about 1400 a day!

According to an article at ABC-News detailing the results from the National Weight Control Registry, a database of people who have lost atleast 30-pounds and maintained their weight-loss for at least one year, that's how many calories they eat on average to maintain their weight.

This most recent look at a sampling of 2,700 people in the database, most of whom were women, found that all reported eating about 1,400 calories per day. The number of registrants following a low-carb diet (<90g carbs) rose between 1995 to 2003, from 6% to 17%, and the percentage of calories from fat also rose from 24% to 29%.

What is troubling, at least to me, is the severely restricted calorie load eaten to maintain the weight loss.

A calorie intake of just 1,400-calories per day is starvation. Such a low intake of calories will not provide adequate levels of essential nutrients for the long-term. If you recall, I wrote recently about a study that showed an increased risk of death following weight loss, [Can Losing Weight Kill You?] and pondered about what could be the reasons for the increased risk.

Since the researchers did not track the type of diet used to lose weight, the nutrient-density of the weight-loss diet or the quality of the maintenance diet in that study, it is impossible to conclude that weight-loss, in and of itself, increases risk of early death. However, as I pointed out, loss of lean body mass may be a risky problem with losing weight - and some dietary approaches actually rob the body of high amounts of lean body mass along with fat loss, namely low-fat, very low calorie diets.

For years the National Weight Control Registry has been used to highlight how a low-fat diet and exercise helps one maintain their weight loss. It is often touted as the "proof" that a low-fat diet works in the long-term. But, and this is where the problem is, the focus is on the percentage of fat in the diet and the amount of exercise, not the nutritional quality or quality of life and health of those being followed. Until we shift our focus, and look at the quality of the diet in terms other than calories (hint, hint - nutrient-density) in the short and long-term, we are not going to solve the obesity trends in the US.

As the ABC-News article painfully shows, no one seems worried about the effect of what is chronic starvation for these people - they're concerned over a rise in the percentage of fat in the diets of those in the registry!

You may remember when I wrote about Basal Metabolic Rate in my previous commentary - very few adults have a basal metabolism of just 1,400 calories, and if they're exercising [that is "active"], 1,400 calories is most definitely not enough calories to meet Active Metabolic Rate [the amount of calories to maintain weight].

With that low an intake of calories, the body is fighting for survival, making all sorts of metabolic compromises through homeostasis, to just survive. Long-term that cannot be viewed as a "good" way to lose weight or proof of "success" for maintaining weight loss.

No one should be expected to starve themselves to reach a healthy weight and no one should be expected to become chronically deficient in essential nutrients because they're not eating enough calories each day to maintain that weight loss.

If you're considering a weight-loss plan, think long and hard about what is expected in the long-term....think about how you'll have to eat once you reach your goal weight....think about the importance of meeting or exceeding your nutrient requirements, even in the weight loss period.

And then consider a controlled-carbohydrate approach - an approach that, when done properly, allows adequate calories, is nutrient-dense, spares lean-body mass and allows you to eat well once you're at your goal weight to maintain not only your new weight, but also your long-term health.

1 comment:

  1. There are animal studies that suggest restricting calories with adequate nutrition (meeting/exceeding nutrient requirements) may have a benefit.

    I haven't seen human data to support that though. There are some people though trying it to see what happens and follow what's called "CRAN" - Calorie Restriction with Adequate Nutrition. If you google for the acronym and the words, you'll find various pages about the lifestyle.

    Personally not something I'd try myself.

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