Alison M. Stephen

Use of food labels and beliefs about diet–disease relationships among university students

OBJECTIVE The purpose of this study was to measure the reported use of nutrition information on food labels by a population of university students and to determine if label users differed from non-users in terms of gender and specific beliefs related to label information and diet-disease relationships, specifically fat and heart disease and fibre and cancer. DESIGN A single-stage cluster sampling technique was used. Data was obtained using a self-administered, validated questionnaire. SETTING The present investigation took place at the University of Saskatchewan, Canada in the autumn of 1997. SUBJECTS : A total of 553 students in randomly selected classes in the College of Arts and Science took part in the survey (92% response rate). The sample consisted of roughly equal numbers of males and females, most between the ages of 18 and 24. RESULTS There were approximately equal numbers of label users and non-users among males, while label users outnumbered non-users by almost four to one among females. The importance of nutrition information on food labels was the only belief that differed significantly between label users and non-users for both sexes. For females, no other beliefs distinguished label users from non-users. However, for males, significant differences were found between label users and non-users on the beliefs that nutrition information is truthful and that a relationship between fibre and cancer exists. CONCLUSIONS Females appear to use food labels more often than do males. The only consistently observed difference between label users and non-users (male and female) was that users believed in the importance of nutrition information on food labels while non-users did not.

The effect of a controlled manipulation of maternal dietary fat intake on medium and long chain fatty acids in human breast milk in Saskatoon, Canada.

BackgroundFew studies in recent years have demonstrated the effect of maternal diet on fatty acid composition of human milk.MethodsFourteen free-living lactating women participated in a cross-over dietary intervention study, consuming a low fat diet (17.6% of energy as fat, 14.4% of energy as protein, 68.0% of energy as carbohydrate) and a high fat diet (40.3% of energy as fat, 14.4% of energy as protein, 45.3% of energy as carbohydrate) each for periods of 4 days, in randomised order. Each mother was her own control. Mature milk samples were collected during each period and analysed for medium and long chain fatty acids.ResultsThe concentration of medium chain fatty acids (MCFA), was 13.6% in breast milk for the low fat diet compared to 11.4% for the high fat (p < 0.05). Arachidonic acid (C20:4n-6) levels were significantly higher in breast milk when women consumed the low fat diet. Increased dietary intake of stearic acid (C18:0) and alpha-linolenic acid (C18:3n-3) on the high fat diet significantly increased proportions of these fatty acids in breast milk (p < 0.05) in 4 days.ConclusionsChanging maternal dietary fat intake has a rapid response in terms of changes to fatty acids in breast milk.

Trends in individual fat consumption in the UK 1900–1985

Mortality from coronary heart disease is decreasing in a number of Western countries, although the pattern of the decrease differs from country to country. In the UK the mortality rate from coronary heart disease has declined since 1979, whereas in the USA mortality from this disease began to fall in 1968 and has continued since that time. Of many factors suggested as reasons for the decline, diet has been implicated, particularly dietary fat intake. However, food balance information suggests little change in fat intake. A recent examination of all published studies from the USA where individual fat intake has been reported indicated that fat intake in that country has fallen steadily since the mid 1960s. The present study describes a similar compilation of all published studies from the UK giving individual fat intakes. Ninety-seven studies, representing information for 24,045 individuals, were used. Studies ranged in size from two to 3581 individuals and were drawn from all regions of the UK. Most studies used 7 d weighed intakes as the method of dietary assessment. Quadratic regression equations were applied to the fat intakes from all studies over time, with each study weighted by the number of individuals surveyed. Data were also divided into 10-year periods and weighted fat intakes for each decade were calculated. Data were expressed for all studies, then subdivided into males, females, children and the elderly. Comparisons between Scotland and the South-East of England were made. Results indicate that fat represented 30% or less of dietary energy in the UK until the 1930s, when it began to rise. This rise was curtailed by rationing during and after the Second World War, after which the rise continued, reaching a plateau of about 40% energy in the late 1950s, with little change until the late 1970s. Trends were similar in all age-groups, but less change has occurred recently in Scotland compared with South-East England. These results differ from the pattern in the USA and suggest that if greater changes in mortality from coronary heart disease are to be seen in the UK a greater reduction in dietary fat intake will have to occur.

Whole grains — impact of consuming whole grains on physiological effects of dietary fiber and starch

Much of the present research on the physiological effects of dietary fiber and starch has been done on sources isolated from the parent material, and it is not clear whether they have the same effects if fed in the intact or whole grain. For dietary fiber, physiological effect depends on extent of fermentation in the large intestine, and this is influenced by chemical composition, solubility, physical form, and presence of lignin or other compounds. All of these factors are altered by isolation of a fiber source from the whole grain, and hence effects of eating fiber vary. Similarly, physical form and presence in the whole grain will affect digestibility of starch in the small intestine, which in turn influences the glycemic response and colonic effects determined by the extent of malabsorption and entry into the colon. Starch that enters the colon is fermented and produces short-chain fatty acids, particularly butyrate, which is necessary to maintain a healthy mucosa. Hence, their presence within the whole grain may have important implications for health for both dietary fiber and starch. Evidence indicates that such effects are beneficial and that whole-grain consumption should be encouraged.

Effect of oat hull fiber on human colonic function and serum lipids

ABSTRACT Oat hull fiber is an insoluble source of dietary fiber, derived from the outermost layer of the oat grain. The effect of oat hull fiber on colonic function and serum lipids was investigated by conducting a controlled study on 10 healthy males, aged 20–37, who ate, for two three-week periods, a controlled low fiber diet (13.1 g of nonstarch polysaccharide [NSP]/day), and the same diet with 25 g of oat hull fiber per day incorporated into foods, providing 17 g of NSP/day. Fecal weight increased from 113 ± 10.4 to 155 ± 10.8 g/day (P < 0.001) with no change in transit time or serum lipids. Fermentation of oat hull fiber was studied by analysis of feces for NSP. Excretion of NSP increased from 2.0 g/day excreted to 19.7 g/day, indicating that no degradation had occurred. Oat hull fiber is therefore resistant to fermentation in the human colon, has no effect on serum lipids, and provides no energy to the body

Food information programs: A review of the literature

This paper summarizes existing evidence on the impact of food information programs. Published and unpublished literature produced within the past decade was searched and reviewed. Relevant data were tabulated and key findings summarized. Food information programs are becoming increasingly popular as tools to help consumers select a healthy diet. The key feature of a food information program is a package logo on foods meeting nutrition criteria set by the program s administering body. The logo acts as a health message. Several countries, including Canada, have adopted food information programs. Critics believe that these programs oversimplify the concept of healthy eating, that consumers misinterpret the logo s meaning, that licensing fees prohibit small companies from participating, and that the programs are limited to purchase behaviour and do not necessarily have an impact on dietary intake. Consumers report support for the programs and are able to interpret a logo s meaning accurately. In addition, evidence shows the programs have had a positive impact on the nutrient composition of foods. Research is still needed, however, to establish the impact of such programs on food purchases and dietary intake, and the overall and long-term effectiveness of the programs as a nutrition intervention.

Increasing complex carbohydrate in the diet: Are the benefits due to starch, fibre or decreased fat intake?

Abstract ‘Nutrition Recommendations’ suggests that Canadians should consume 30% of the dietary energy as fat and 55% of energy as carbohydrate, from a variety of sources. While much emphasis has been placed on reducing fat intake, less work has been done on changing carbohydrate intake, with the result that little change in intake of this nutrient has been seen over the last twenty years. New evidence indicates that there may be direct advantages for health of increasing carbohydrate consumption, rather than just as a substitute energy source when fat is removed. Research since 1980 has indicated that not all starch consumed is digested and absorbed in the small intestine, but that 8–10% may reach the colon, where it is fermented by the resident microflora. Fermentation of starch results in a higher proportion of the short chain fatty acid butyrate than fermentation of dietary fibre; this may be of importance since butyrate is a preferred energy source for the colonic mucosal cells, and has been shown to have anticancer properties in vitro . Benefits for health of starch consumption are emerging with new research; the public must be informed of these findings and encouraged to consume a high starch diet.