Last week you read about a bike ride that should've ended badly. I should've never been able to ride 77 miles in just over four hours after fasting for 13 hours one Sunday in October, but I did.

I decided to share that story with you as an example of how dieting is more than just science and as a way to introduce a study published about two months ago in the Lancet. The study seemingly shatters a prior scientific belief about dieting. The research found little difference between the effectiveness of weight loss and the rate at which that weight loss occurred.Prior to this study, most believed that weight loss of more than a pound or two a week by severely limiting calories made the long-range goal of the diet to keep the weight lost off permanently far more difficult. That's because much of immediate weight loss from a fad diet is not body fat but a combination of water and muscle not exactly the stuff most dieters are hoping to lose.Muscle burns far more calories than fat even when your body is at rest so dieters who lose weight quickly and thereby muscle in the process find the lost weight returns quickly once a normal amount of food is consumed. Less muscle means a reduced need for calories, sometimes 300 or 400 or so.At least that's the traditional explanation. And I do believe that for the most part it remains true.But a wrench has been thrown into the works. And when that wrench comes from a publication as highly regarded as the Lancet, it's worthy of discussion or at least a "Fitness Master" column.In the aforementioned study, Australian researchers gathered 200 obese subjects between the ages of 18 and 70 and split the group approximately in half. One half consumed what I would call a fad and foolish diet, replacing breakfast, lunch, and dinner with Optifast shakes.This group's daily caloric total was no more than 800 calories and sometimes as low as 450 the equivalent of eating no more than one big bagel with one ounce of cream cheese. Such a diet was designed to produce a 15 percent loss of overall body weight in 12 weeks.In other words, a 240-pound man at the start of this diet was supposed to weigh 204 pounds in 84 days.The other group used the Optifast shake once or twice a day but cooked their other meals in accordance to the Australian Guide to Healthy Eating. The weight-loss goal remained the same 15 percent of overall body weight but the time in which to do so tripled.You'd think that the more relaxed pace would lead to a greater success ratio, but the opposite occurred. More than 8 out of 10 in the lose-it-quickly group dropped at least 12.5 percent of their overall body weight in 12 weeks, yet only 6 out of 10 in the slow-but-steady group reached the same mark 24 weeks later.You'd also think that the second group would have an easier job keeping off the lost weight, but that really didn't occur. Over the long term, the weight that remained lost regardless of the diet was just about the same.So what can you do with this new info? What I frequently tell you to do: apply it in terms of what you know of yourself.While one study is not going to change my dieting philosophy, I do think these results might suggest a bit more leeway. So if you're more of an all-or-nothing type, you might benefit from a stricter diet than I've suggested in the past.That's one of the reasons whyI wrote about my experience of riding long and hard on a doctor-ordered fast last week. It's also is an example of a type of dieting that, according to science, shouldn't be successful.While our knowledge of science can certainly help any diet, there is certainly another element to it one that could be seen as an art predicated on a profound knowledge of your own body.So if you do decide to try a severely limited-calorie diet, I would suggest counteracting the muscle-wasting effect of it by increasing your degree of weightlifting during it. Estimate the number of cals you'd burn from that increase and add that amount to your diet.In other words, if the diet book tells you to eat no more than 1000 cals a day, do that only on the days you do not lift weights. On the days you do lift, keep the pace of the lifting quick, keep the weight used moderately heavy for you, and eat an addition 300 calories for every 45 minutes of lifting you do.Make the extra cals a mixture of protein and complex carbs.By doing this, you might actually get the best of both theories: the immediate weight loss that so many dieters seem to need in order to continue and less muscle loss, which will allow you to keep off more of the weight lost later.