Nutritionist Does Twinkie and Steak Diet, Loses Weight A nutritionist tries a Twinkie diet and gets thinner but not healthier.

Sept. 30, 2010 -- It's either a kid's dream or a dietician's nightmare: nutritionist Mark Haub ate Twinkies and Nutter Butters, steak, milk, and a multivitamin for a month and lost 15 pounds.

Haub, an associate professor of nutrition at Kansas State University, wasn't indulging in this snack cake binge for kicks. He wanted to open up a debate for his students: as long as basic nutritional needs are met, is it what you eat, or just how much, that counts?

"I knew I could lose weight doing this, but I had no idea what was going to happen to cholesterol. That's why I made it only four weeks because I had no idea how it would affect my health," he says.

The thing is, he began to feel healthier. He had more energy, stopped snoring, and not only did he lose enough weight to drive down his overall cholesterol and body mass index (BMI), his good HDL cholesterol crept up two points and his blood glucose -- despite all that cream filling -- dropped 17 percent.

Haub began the experiment on Aug. 25, restricting his caloric intake to 1800 calories a day and keeping his physical activity the same, but with eating predominantly junk food: four to five processed snack cakes a day along with whole milk, canned or frozen vegetables, a multi-vitamin, protein supplement and things like chips and ribs.

The cholesterol changes were a surprise, he says, and he's pleased with the weight loss. But Haub is careful to point out that this was an experiment, not an attempt at to create an optimal diet. He wouldn't advise anyone to try it themselves because the long-term effects of this kind of eating are still unknown.

Nevertheless, he's extended the diet in a modified version until he loses eight more pounds and reaches his goal BMI. Once the diet has worked, he might cut back on the snack cakes, he says.

Diet experts, however, warn that the initial changes in Haub's cholesterol and weight could be deceiving. Losing 15 pounds will always make you feel healthier, they note, but over time, a diet rich in processed, sugary food is no way to improve health.

"He's not the first person to lose weight on an unhealthy diet. You could eat all chocolate cake and lose weight as long as you didn't eat too much of it. Staying on this diet forever and he'd have some unpleasant consequences," says Carla Wolper, a researcher at the St. Luke's Hospital Obesity Center.

Diet Lessons From Nutrition Prof

Haub's diet exercise grew out of a discussion among him and his colleagues. They wanted to know, "does it matter where your energy comes from?" he says. There was talk about a honey bun diet, or just butter, sugar and whey protein, but "I didn't think I could eat that for more than a day," Haub says.

Though nutritionists have generally supported eating whole grains, fresh fruits and vegetables, and not a lot of processed foods, Haub hopes his experiment pushes the envelope of dieting and has people asking questions.

"I've done zone, low-carb, low-fat, and other diets and I still had high cholesterol. My risk for heart attack decreased 1 percent in four weeks on this diet. Is that healthy? That's the question I want students to ask," he says.

According to diet experts, Haub's results are not surprising; he ate fewer calories and he lost weight, and this has always been the case.

"We've made altogether too much over fat versus carbs and it's a huge distraction for the most part. The fundamental truth is that at energy balance, calories in versus calories used, determines weight, and this reinforces that," says Dr. David Katz, director of the Yale Prevention Research Center.

And in the short-term, weight loss alone is enough to see other health benefits, such as higher healthy HDL cholesterol, no matter how you achieve it.

"If we have learned anything over the years about nutrition it is that in the short term, your body doesn't care where the calories come from. The body is an effective furnace and will burn anything you throw into it, as long as it's not toxic," says Dr. Darwin Deen, director of the Regional Center for Clinical Nutrition Education at the Montefiore Medical Center.

"This process of living off of your stores is beneficial because it keeps your insulin levels low and after a while you have less body fat which is healthier," he says.

But over the long haul, less fat does not equal a healthier body, Katz says.

Someone who developed a cocaine habit and stopped eating would see effects similar to those Haub experienced: a lowering of cholesterol and decreased body fat, but no one would say they were healthy, he points out.

Similarly, Haub says that his success with this diet highlights how our society focuses on weight loss to a fault. " I feel our focus is on the wrong target (obesity) and by focusing on that target, the message of how [we get there] is lost," Haub says.

Short-term Gain, Long-term Pain

So when would the snack-cake fest start to weigh a dieter down?

Haub says it's possible that in moderate quantities, he may be able to keep eating processed foods and experience no detriment.

But given the lower volume of food that Haub is allowed to eat to stay within caloric restrictions while eating these cakes, and the lack of nutrition they provide, diet experts predict that cravings and nutritional deficiencies would start to take their toll in a matter of months.

"The impact of an unhealthy diet is felt in years, not weeks," says Montefiore's Deen. "Four weeks … was not enough time to have any health problems resulting from long-term lack of nutrients."

Antioxidants, phytonutrients, and fiber were all lacking from Haub's meal plan, experts say, and data connects these things with lower cancer risk, longevity, and overall health.

And while Haub's blood tests suggest health improvement, that doesn't mean that his body is healthy or that he'll feel good over months of eating like this, Katz says.

"Nothing in this blood work tells us what his cancer risk would be in the next 20 years."

"One of the things I hope people recognize is that the diets we choose need to be more than just losing weight as fast as possible. We also want to find health and it's combining those two goals that should dictate the kinds of diets we try and the kinds we professionals recommend," Katz added.

ABC News' Lee Feran contributed on this report