In 1979, Mickelsen et al (full text here ) wanted to see if people can eat a diet high in regular refined wheat bread and lose body fat. Their rationale follows:
This paragraph seems to fit our times though written more than 30 years ago:
"Incorrect assumptions have taught that bread should be eliminated from weight control plans; this idea has been fostered by the recommendations and instructions of many weight-reducing plans (2). The instructions of many fad-type diets state that 'starchy' foods such as bread and potatoes should be avoided...Measurement of food intake and caloric deposition in the carcasses of rats fed a high-fat or a natural grain diet indicated that for each 1000 cal intake the high-fat fed rats retained twice as many calories as the grain-fed animals (3)."
To find out if a diet high in wheat grain would have the same effect on humans as on rats (reduced caloric retention), Mickelsen et al recruited 16 overweight college males, all of whom wanted to lose between 4.5 and 12 kg (10 to 26 pounds).
The subjects all agreed to eat all meals in a cafeteria, avoid alcoholic beverages, and consume 12 slices of wheat bread every day (four slices at each of three meals) for eight weeks. Mickelsen et al randomized the subjects into two groups, one of which received high fiber bread and the other received white bread (i.e. made from refined wheat). All subjects “were instructed that to lose weight, they would have to restrict caloric intake” but they were allowed to eat as much as desired at meals and were also allowed to snack between meals as desired.
The two types of bread differed in several respects. The high fiber bread supplied 50 calories and two grams of fiber per slice, while the regular bread supplied 70 calories and only one-tenth of a gram of fiber (the high fiber bread had 20 times the fiber of the regular bread). The high fiber bread had about half as much fat and twenty-five percent less digestible carbohydrate than the regular bread. The high fiber bread had about 50 percent more iron, present in the added fiber, and was enriched with calcium because the researchers anticipated that the high fiber bread would reduce calcium absorption, although it turned out that the higher fiber intake did not reduce calcium absorption.
Thus, each day of the study period, those eating the high fiber bread ingested 600 calories and 108 g carbohydrate from wheat bread, and those eating the regular bread ingested 840 calories and 156 g carbohydrate from wheat bread.
For comparison, Ezekiel Bread, a favorite of Ripped author Clarence Bass, supplies 11 g of digestible carbohydrate, 3 g of fiber, 4 g of protein, and 65 calories per slice (the label lists 80 calories per slice but that was derived by including the potential caloric value of the indigestible fiber, which is unavailable to us). A loaf of Ezekiel Bread has 20 slices, so the subjects of this study ate more than half a loaf of bread every day. Twelve slices of Ezekiel Bread supplies only about 780 calories, about half of the 1500 calorie intake that would produce weight loss in many women.
So did eating all this wheat make their bellies fatter, or flatter?
Over the eight week period, the subjects eating the regular bread lost an average of 6.25 kg (about 14 pounds; range 4.2 to 7.3 kg), while the subjects eating the high fiber bread lost an average of 8.77 kg (about 19 pounds; range 6.2 to 11.4 kg). Thus, those eating 12 slices of white bread daily lost an average of one and three-quarters pounds of body weight each week; and those eating 12 slices of high fiber daily lost an average of two and two-fifths pounds of body weight each week. They did not make any changes in activity level.
Of interest, the subjects succeeded in reducing their caloric intake by 25 to 38 percent while simultaneously experiencing a decrease in hunger. At the end of the study, the subjects consuming the high fiber bread reported that they did not feel hungry at any time. Two of the subjects eating the regular bread did feel hungry at the end of the study, one of those only before meals.
The group eating the regular bread had a decrease in serum cholesterol from 231 to 155 mg/dL, and the group eating the high fiber bread decreased serum cholesterol from 224 to 172 mg/dL.
Follow-ups on 9 of the participants at 3 months, 6 months, and 9 months found that those four who stopped eating the bread regained the weight they had lost, while those five who continued to eat the bread (regular, higher calorie) either maintained most of their weight loss or lost even more weight.
In summary, this study found that all participants reduced their hunger, cholesterol levels, and body weight by deliberately consuming a dozen slices of bread each day, four slices at each of three meals, more than half a loaf of bread daily, regardless of whether the bread was high in fiber or made from refined white flour. Those who abandoned this regimen gained the weight back and those who continued to eat a diet revolving around refined white bread maintained their weight loss or lost even more weight.
Eating 12 slices of wheat bread did not
- increase their hunger (it decreased their hunger)
- increase body weight (it resulted in weight loss by reducing other food intake)
- increase their blood sugar levels (they had no change in blood sugar levels)
- raise the risk of heart disease (it decreased the levels of a major heart disease risk factor, total serum cholesterol)
All this without inducing the headaches, nausea, malaise, fatigue, and constipation that commonly affect people, particularly women, when consuming high-fat, low-carbohydrate diets.
This study using Caucasian subjects resonates with the experience of millions of Asians who eat an average of one pound of dry rice daily and maintain low body fat levels throughout their lifespan.
|Source: Abdullah et al (full text pdf)|