Genotype-based personalised nutrition for obesity prevention and treatment: are we there yet?

Interactions between genotype and dietary intake include genetic moderation of the effect of dietary intake on disease development (nutrigenetics). Research on nutrigenetics has focused mainly on single-nucleotide polymorphisms (SNPs) and supports the notion that interactions between genes, diet, other lifestyle factors, disease, and time (life cycle span), contribute to the risk of most polygenic nutritionrelated diseases. Typically, genotype-based personalised nutrition involves genotyping for a number of susceptibility SNPs associated with the prevention, or management, of a particular disease. Dietary advice is then personalised to the individual's genotype to ensure optimal prevention or treatment outcomes. To ensure evidence-based practice, research design and methodology, applied in the investigation of relevant associations, and confirmation of causality, should be appropriate and rigorous. The process of identifying SNPs associated with disease patterns is ongoing. Of note is that the combined effect on body mass index of the SNPs at the currently confirmed 32 loci is a modest 1.45%, bearing in mind that the estimated heritability of obesity is 40-70%. Conclusions formulated by various researchers on the translation of nutrigenetics research into personalised nutrition, including obesity prevention and management, indicate that scientists hold the opinion that more research is necessary before evidence-based practice in this area can be guaranteed

Application and interpretation of multiple statistical tests to evaluate validity of dietary intake assessment methods

BACKGROUND:Several statistical tests are currently applied to evaluate validity of dietary intake assessment methods. However, they provide information on different facets of validity. There is also no consensus on types and combinations of tests that should be applied to reflect acceptable validity for intakes. We aimed to 1) conduct a review to identify the tests and interpretation criteria used where dietary assessment methods was validated against a reference method and 2) illustrate the value of and challenges that arise in interpretation of outcomes of multiple statistical tests in assessment of validity using a test data set. METHODS: An in-depth literature review was undertaken to identify the range of statistical tests used in the validation of quantitative food frequency questionnaires (QFFQs). Four databases were accessed to search for statistical methods and interpretation criteria used in papers focusing on relative validity. The identified tests and interpretation criteria were applied to a data set obtained using a QFFQ and four repeated 24-hour recalls from 47 adults (18-65 years) residing in rural Eastern Cape, South Africa. RESULTS: 102 studies were screened and 60 were included. Six statistical tests were identified; five with one set of interpretation criteria and one with two sets of criteria, resulting in seven possible validity interpretation outcomes. Twenty-one different combinations of these tests were identified, with the majority including three or less tests. Coefficient of correlation was the most commonly used (as a single test or in combination with one or more tests). Results of our application and interpretation of multiple statistical tests to assess validity of energy, macronutrients and selected micronutrients estimates illustrate that for most of the nutrients considered, some outcomes support validity, while others do not. CONCLUSIONS: One to three statistical tests may not be sufficient to provide comprehensive insights into various facets of validity. Results of our application and interpretation of multiple statistical tests support the value of such an approach in gaining comprehensive insights in different facets of validity. These insights should be considered in the formulation of conclusions regarding validity to answer a particular dietary intake related research question

Non-communicable disease risk factors and treatment preference of obese patients in Cape Town

Background: Insights into the characteristics of treatment seekers for lifestyle changes and treatment preferences are necessary for intervention planning. Aim: To compile a profile of treatment-seeking obese patients with non-communicable diseases (NCDs) or NCD risk factors and to compare patients who choose group-based (facility-based therapeutic group [FBTG]) versus usual care (individual consultations) treatment. Setting: A primary healthcare facility in Cape Town, South Africa. Methods: One hundred and ninety-three patients were recruited in this cross-sectional study. Ninety six chose FBTG while 97 chose usual care. A questionnaire, the hospital database and patients’ folders were used to collect data. Weight, height and waist circumference were measured. STATA 11.0 was used for descriptive statistics and to compare the two groups. Results: The subjects’ mean age was 50.4 years, 78% were women and of low education levels and income, and 41.5% had type 2 diabetes, 83.4% hypertension and 69.5% high cholesterol. Mean (s.d.) HbA1c was 9.1 (2.0)%, systolic BP 145.6 (21.0) mmHg, diastolic BP 84.5 (12.0) mmHg, cholesterol 5.4 (1.2) mmol/L), body mass indicator (BMI) 39.3 (7.3) kg/m2 and waist circumference 117 (12.6) cm). These figures were undesirable although pharmacological treatment for diabetes and hypertension was in place. Only 14% were physically active, while TV viewing was > 2h/day. Mean daily intake of fruit and vegetables (2.2 portions/day) was low while added sugar (5 teaspoons) and sugar-sweetened beverages (1.3 glasses) were high. Usual care patients had a higher smoking prevalence, HbA1c, number of NCD risk factors and refined carbohydrate intake, and a lower fruit and vegetable intake. Conclusion: Treatment seekers were typically middle-aged, low income women with various modifiable and intermediate risk factors for NCDs. Patients choosing usual care could have more NCD risks. Keywords: Non-communicable diseases; primary health care; family medicine; obesity; diabetes; treatment preference; dietary intake; NCD risk factors; group-based treatment; stages of chang

Illustration of the Importance of Adjustment for within- and between-Person Variability in Dietary Intake Surveys for Assessment of Population Risk of Micronutrient Deficiency/Excess Using an Example Data Set

Nutrition intervention decisions should be evidence based. Single 24-h recalls are often used for measuring dietary intake in large dietary studies. However, this method does not consider the day-to-day variation in populations’ diets. We illustrate the importance of adjustment of single 24-h recall data to remove within-person variation using the National Cancer Institute method to calculate usual intake when estimating risk of deficiency/excess. We used an example data set comprising a single 24-h recall in a total sample of 1326 1–<10-year-old children, and two additional recalls in a sub-sample of 11%, for these purposes. Results show that risk of deficiency was materially overestimated by the single unadjusted 24-h recall for vitamins B12, A, D, C and E, while risk of excess was overestimated for vitamin A and zinc, when compared to risks derived from usual intake. Food sources rich in particular micronutrients seemed to result in overestimation of deficiency risk when intra-individual variance is not removed. Our example illustrates that the application of the NCI method in dietary surveys would contribute to the formulation of more appropriate conclusions on risk of deficiency/excess in populations to advise public health nutrition initiatives when compared to those derived from a single unadjusted 24-h recall

Clothing needs and related problems of female social pensioners in Stellenbosch

This article reports on a study of the clothing needs and related problems of female social pensioners in Stellenbosch. The sample consisted of 107 coloured women who were 60 years and older, and non-institutionalized. A structured questionnaire was used to gather the data during interviews in the respondents' homes. It was found that most of the respondents buy their clothes at stores in Stellenbosch. They prefer certain stores which sell clothes at affordable prices. Style preferences include cardigans, gathered skirts, loose-fitting jackets, and dresses with front openings. The women value clothes that fit well, are comfortable and are aesthetically pleasing. The respondents felt that their clothes are adequate for their activities but that they lack certain clothing items, such as winter sleepwear and underwear

A food photograph series for identifying portion sizes of culturally specific dishes in rural areas with high incidence of oesophageal cancer

Rural areas of the Eastern Cape (EC) Province, South Africa have a high incidence of squamous cell oesophageal cancer (OC) and exposure to mycotoxin fumonisin has been associated with increased OC risk. However, to assess exposure to fumonisin in Xhosas—having maize as a staple food—it is necessary to determine the amount of maize consumed per day. A maize-specific food frequency questionnaire (M-FFQ) has recently been developed. This study developed a food photograph (FP) series to improve portion size estimation of maize dishes. Two sets of photographs were developed to be used alongside the validated M-FFQ. The photographs were designed to assist quantification of intakes (portion size photographs) and to facilitate estimation of maize amounts in various combined dishes (ratio photographs) using data from 24 h recalls (n = 159), dishing-up sessions (n = 35), focus group discussions (FGD) (n = 56) and published literature. Five villages in two rural isiXhosa-speaking areas of the EC Province, known to have a high incidence of OC, were randomly selected. Women between the ages of 18–55 years were recruited by snowball sampling and invited to participate. The FP series comprised three portion size photographs (S, M, L) of 21 maize dishes and three ratio photographs of nine combined maize-based dishes. A culturally specific FP series was designed to improve portion size estimation when reporting dietary intake using a newly developed M-FFQ

Has Food Security and Nutritional Status Improved in Children 1–<10 Years in Two Provinces of South Africa between 1999 (National Food Consumption Survey) and 2018 (Provincial Dietary Intake Study (PDIS))

The 1999 National Food Consumption Survey in South Africa showed that food insecurity (hunger) was prevalent in households with children aged one to &lt;10 years. A repeat of the survey in two provinces: Gauteng (GTG) and the Western Cape (WC) was undertaken in 2018. Results showed that in all domains (living areas) in GTG, food shortage prevalence decreased between 1999 and 2018, from 55.0% to 29.6% in urban informal areas, from 34.1% to 19.4% in urban formal areas and from 42.1% to 15.6% in rural areas. While the prevalence of food shortage in urban formal areas in the WC remained similar in 2018, prevalence decreased from 81.8% to 35.7% in urban informal areas and from 38.3% to 20.6% in rural areas. Energy and macronutrient intakes improved significantly in GTG between 1999 and 2018 but not in the WC; intakes were significantly higher in the WC at both time points. The only significant change in stunting, wasting, overweight and obesity prevalence was that 7&ndash;&lt;10-year-olds in GTG were significantly more likely to be wasted (BAZ &lt; 2SD) in 2018 than in 1999 (20.2% versus 6.9% respectively). In the WC, 1&ndash;3-year-olds were significantly more likely to be obese in 2018 than in 1999 (8.1% versus 1.7% respectively) and 7&ndash;&lt;10-year-olds were less likely to be stunted (14.5% versus 4.9% respectively). There were significant negative correlations between the hunger score and dietary variables in both provinces in 1999. In GTG in 2018, only the correlation with fat intake remained while there were still several significant correlations in WC in 2018. Changes in top 12 energy contributors reflect a shift to high or moderate energy foods low in nutrients from 1999 to 2018. Nutrient dense (high micronutrients, low energy/g) foods (e.g., fruit) fell off the list in 2018. Logistic regression analyses reflect the importance for food security of having a parent as head of the household and/or caregiver, and parents having grade 12 or higher education and being employed. We conclude that food security nutritional status indicators improved amongst 1&ndash;&lt;10-year-old children especially in GTG between 1999 and 2018. However, the shift to poorer food choices and increase in wasting in older children and overweight in younger children are of concern

Fat Mass and Obesity-Associated (FTO) Gene Polymorphisms Are Associated with Physical Activity, Food Intake, Eating Behaviors, Psychological Health, and Modeled Change in Body Mass Index in Overweight/Obese Caucasian Adults

The fat mass and obesity-associated (FTO) gene is currently recognized as the most robust predictor of polygenic obesity. We investigated associations between the FTO rs1421085 and rs17817449 polymorphisms and the FTO rs1421085–rs17817449 haplotype and dietary intake, eating behavior, physical activity, and psychological health, as well as the effect of these associations on BMI. N = 133 treatment seeking overweight/obese Caucasian adults participated in this study. Genotyping was performed from whole blood samples. Weight and height was measured and a non-quantified food frequency questionnaire was completed to assess food group intake. Validated questionnaires were completed to assess physical activity (Baecke questionnaire), psychological health (General Health questionnaire, Rosenburg self-esteem scale and Beck Depression Inventory), and eating behavior (Three Factor Eating questionnaire). The risk alleles of the FTO polymorphisms were associated with poorer eating behaviors (higher hunger, internal locus for hunger, and emotional disinhibition scores), a higher intake of high fat foods and refined starches and more depressive symptoms. The modeled results indicate that interactions between the FTO polymorphisms or haplotypes and eating behavior, psychological health, and physical activity levels may be associated with BMI. The clinical significance of these results for implementation as part of weight management interventions needs further investigation

Weight-loss strategies of South African female university students and comparison of weight management-related characteristics between dieters and non-dieters

Abstract Background Female university students are at risk for weight gain and use of inappropriate weight-loss strategies. By gaining a greater understanding of the weight-loss strategies used by and weight management related characteristics of these students, effective weight management interventions for this vulnerable group can be developed. Methods Two hundred and fifty female students from South Africa universities, aged 18–25 years, participated in this cross-sectional study; 162 attempted weight loss during the year preceding the study (dieters) and 88 were non-dieters. Weight and height were measured and BMI (kg/m 2 ) computed. A self-administered questionnaire was used to record all other variables. Weight loss strategies were described for dieters and compared between BMI groups within the dieters group. Weight management related characteristics were compared between dieters and non-dieters. Statistical tests included Pearson Chi-square test, independent samples t-test or Mann-Whitney U test (depending on distribution of the data). Predictors for a higher BMI and being overweight/obese (BMI ≥25 kg/m 2 ) were identified using regression models. Results Healthy weight-loss strategies included increased exercise and fruit/vegetable intake and decreased intake of sugar and fat containing items; unhealthy methods included eating little food and skipping meals; and extreme weight loss strategies included laxatives and vomiting. The most commonly used weight-loss product was Herbex. Dieters were characterized by a higher BMI, overestimation of their weight (especially normal weight students), dissatisfaction with weight and select body parts, higher intake of breakfast and healthy foods, lower intake of unhealthy foods, higher levels of vigorous physical activity, higher use of select informal weight-loss information sources and experiencing more pressure to lose weight from mothers, siblings and friends. Predictors of higher BMI and/or increased risk for BMI ≥25 included weight-loss attempt during the past year, race, dissatisfaction with waist, perception of currently being “chubby,” and higher frequencies of intake of a snack and fatty foods. Conclusion Attempting weight-loss is common among female students and predicts BMI. Healthy (mainly), unhealthy and extreme weight loss methods are used. Dieters are characterized by a less realistic body image, lower body satisfaction, higher pressure to lose weight, use of informal weight-management information and a healthier life-style

Health status of primary school educators in low socio-economic areas in South Africa

Background: Non-communicable Diseases (NCDs) are major health concerns in South Africa. According to the life cycle approach NCD prevention strategies should target children. Educators are important external factors influencing behaviour of learners. The objective of this study was to assess the prevalence of selective NCD risk factors in educators of primary school learners. Methods: A cross-sectional design was used to assess the body mass index (BMI) and waist circumference (WC), blood glucose (BG), cholesterol (BC), blood pressure (BP), perceived health and weight, and parental NCD history of 517 educators in the Western Cape of South Africa. Results: The sample included 40% males and 60% females; 64% urban and 36% rural, 87% were mixed ancestry, 11% white and 2% black. Mean age for the total group was 52 ± 10.1 years, BMI 30 ± 1.2 kg/m2 (31% overweight, 47% obese), diastolic BP 84 ± 10.0 mmHg, systolic BP 134 ± 18.7 mmHg (46% high BP), BG 4.6 ± 2.3 mmol/L (2% high BG), BC 4.4 ± 0.9 (30.4% high BC) and WC 98 ± 14.1 cm for males (38% high WC) and 95 ± 15.3 for females (67% high WC). BMI was higher (p = 0.001) and systolic (p = 0.001) and diastolic (p = 0.005) BP lower in females. Rural educators were more obese (p = 0.001). BMI (p = 0.001) and systolic BP (p = 0.001) were lower in younger educators. Correct awareness of personal health was 65% for BP, 79.2% for BC and 53.3% for BG. Thirty-eight percent overweight/obese females and 33% males perceived their weight as normal. Conclusion: The findings of this study demonstrated a number of characteristics of educators in the two study areas that may influence their risk for developing NCDs and their potential as role models for learners. These included high levels of obesity, high blood pressure, high waist circumference, high cholesterol levels, and high levels of blood glucose. Furthermore, many educators had a wrong perception of their actual body size and a lack of awareness about personal health