Fast food not making us fat?

Fast food not making us fat?

All calories are not created equally, as exhibited by a three-month fast-food diet.

BASED on popular perception, a steady diet of fast-food meals would guarantee packing on few extra pounds and having adverse health outcomes.

After consuming 270 consecutive meals from McDonald's and losing 37 lb., Iowa high school science teacher John Cisna had a different tale to tell.

Inspired by the 2004 documentary "Supersize Me," Cisna and three of his sophomore science students embarked on a 90-day experiment documenting the effects of eating an exclusively fast-food diet.

However, unlike the 2004 documentary, the group did exactly the opposite by starting with an individual, Cisna, who was overweight, not exercising and had cholesterol levels in the high-risk category for heart disease.

The approach to the assignment was to calculate a 2,000-calorie-per-day diet from the McDonald's menu that also stayed within the recommended daily dietary allowances for nutrients like carbohydrates, protein, fat and cholesterol. In addition to the reduction in calorie intake, Cisna also exercised 45 minutes a day.

In order to stay within the nutritional limits, Cisna did have to consume some lower-calorie options like egg white sandwiches and salads, but dinner always consisted of a value meal. Cisna told KCCI news he did not eat just salads; he had Big Macs, quarter-pounders with cheese and even an occasional ice cream treat.

To be fair, a reduction in overall calorie intake and increase in physical activity would normally result in weight loss for anyone, but the quest for Cisna and his students was to prove that no matter where you dine, as long as you make a conscious effort to watch your dietary intake, you can maintain a healthy weight.

"The point behind this documentary is, 'Hey, it's (a) choice. We all have choices. It's our choices that make us fat, not McDonald's," Cisna said in the KCCI interview.

At the end of the 90-day experiment, Cisna did lose 37 lb., but the proof was in his blood work results. Cisna's cholesterol levels showed an overall decrease, with his low-density lipoprotein ("bad") cholesterol dropping from 170 to a near-optimal level at 113.

As Cisna and his students learned, what you eat, where you eat and how you eat are all controllable factors in maintaining a healthy weight and lifestyle.

Still, as evident in Cisna's experiment and the "Supersize Me" documentary, all calories are not created equally. Cisna's blood work demonstrated that properly managing the macronutrients carbohydrates, fats and proteins can have a positive influence on overall health.

For years, obesity research has focused on total calories consumed and the interaction with diet and body fat, without considering the effect of macronutrients.

The theory, commonly known as calorie-is-a-calorie, is based on the hypothesis that a calorie of protein is equal to a calorie of carbohydrate or a calorie of fat. Essentially, the assumption is that consuming 500 calories' worth of Twinkies is equal to eating 500 calories of chicken.

Separately, macronutrients serve different purposes for the human body. Carbohydrates are the body's main source of fuel, while protein is necessary for growth, tissue repair, making essential hormones and enzymes and preserving lean muscle mass.

Although fat is normally labeled as the cause of weight gain, some fat is necessary for survival. According to the U.S. Department of Agriculture's dietary guidelines, 20-35% of calories should come from fat. As a macronutrient, fat, beyond being an energy source, aids in absorbing certain vitamins and maintaining cell membranes.

More important than the amount of fat consumed is the type of fat eaten. There are two types of fat: saturated and unsaturated. Unsaturated fats — monounsaturated and polyunsaturated — are considered the "good" fats. Saturated fats and trans fats are labeled as "bad" fats because they elevate cholesterol and increase the risk of heart disease.

Most foods contain both saturated and unsaturated fats. Recognizing the total fat, saturated fats and unsaturated fats present in food can further assist individuals in keeping cholesterol levels in an optimal range for good health. However, most food labels do list monounsaturated and polyunsaturated fat because it is not required.

As illustrated in the high school experiment, tracking recommended daily allowances in addition to total calorie count quickly creates an awareness of food items that give consumers more bang for their calorie intake.

For example, in order to get 27 g of protein, one can consume 3.17 oz. of lean pork at 171 calories, 3.0 oz. of lean beef at 180 calories, 1-1/4 cups of raw soy tofu at 236 calories, seven tablespoons of peanut butter at 670 calories or 27 Twinkies at 4,050 calories.

Despite that example, the fat in lean red meat is often misunderstood. Animal proteins are often reported as containing only saturated fat, but in fact, lean beef is half monounsaturated fat — the same fat found in salmon.

 

School lunches

Consuming a balance of the necessary macronutrients for enhancing brain power and maintaining a healthy lifestyle is never more important than for meals served in schools.

USDA's announcement this month that it will allow schools to serve larger portions of lean protein and whole grains (Feedstuffs, Jan. 6) was welcome news for students, parents and schools.

Originally, the standards limited schools to serving an average of 2 oz. of meat per meal, which was only about three chicken nuggets for any student in kindergarten through high school.

 

Future research

Numerous studies over the years have looked at just restricting calories or carbohydrates to lose weight. In most cases, the studies have participants follow different macronutrient-restricted diets, e.g., a low-fat or low-carbohydrate diet.

The participants are given a diet to follow and then are sent off on their own. When the participants fail to stick to the restricted diet and do not lose weight, the perceived research conclusion is to confirm that the only way to lose weight is to reduce calorie intake.

Yet, researchers at the Nutrition Science Initiative (NuSI), founded by Dr. Peter Attia, and science and health journalist Gary Taubes have questioned this philosophy that fat is regulated by the amount of energy we consume and expend. The ultimate question — What causes weight gain? — remains unanswered.

As an alternative hypothesis, NuSI is focusing its research on the macronutrient composition of the diet and its influence on adiposity through its effect on the hormones that regulate the uptake of fat.

Individually, differences in people's DNA mean they will have different hormonal and metabolic responses to the diet. In real life, this becomes evident when two people try the same diet and have different results.

Similar to the high school experiment, the focus of the current NuSI research is to closely monitor participants' food intake and weight by providing all of the food participants are to consume and not assuming what foods they actually ate.

As result, the metabolic effects of diets and differences can be observed in hopes for the answer to prevent the recurrence of obesity in the future.

Volume:86 Issue:02

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