Angeliki Papadaki

Diets with high or low protein content and glycemic index for weight-loss maintenance

BACKGROUNDnStudies of weight-control diets that are high in protein or low in glycemic index have reached varied conclusions, probably owing to the fact that the studies had insufficient power.nnnMETHODSnWe enrolled overweight adults from eight European countries who had lost at least 8% of their initial body weight with a 3.3-MJ (800-kcal) low-calorie diet. Participants were randomly assigned, in a two-by-two factorial design, to one of five ad libitum diets to prevent weight regain over a 26-week period: a low-protein and low-glycemic-index diet, a low-protein and high-glycemic-index diet, a high-protein and low-glycemic-index diet, a high-protein and high-glycemic-index diet, or a control diet.nnnRESULTSnA total of 1209 adults were screened (mean age, 41 years; body-mass index [the weight in kilograms divided by the square of the height in meters], 34), of whom 938 entered the low-calorie-diet phase of the study. A total of 773 participants who completed that phase were randomly assigned to one of the five maintenance diets; 548 completed the intervention (71%). Fewer participants in the high-protein and the low-glycemic-index groups than in the low-protein-high-glycemic-index group dropped out of the study (26.4% and 25.6%, respectively, vs. 37.4%; P=0.02 and P=0.01 for the respective comparisons). The mean initial weight loss with the low-calorie diet was 11.0 kg. In the analysis of participants who completed the study, only the low-protein-high-glycemic-index diet was associated with subsequent significant weight regain (1.67 kg; 95% confidence interval [CI], 0.48 to 2.87). In an intention-to-treat analysis, the weight regain was 0.93 kg less (95% CI, 0.31 to 1.55) in the groups assigned to a high-protein diet than in those assigned to a low-protein diet (P=0.003) and 0.95 kg less (95% CI, 0.33 to 1.57) in the groups assigned to a low-glycemic-index diet than in those assigned to a high-glycemic-index diet (P=0.003). The analysis involving participants who completed the intervention produced similar results. The groups did not differ significantly with respect to diet-related adverse events.nnnCONCLUSIONSnIn this large European study, a modest increase in protein content and a modest reduction in the glycemic index led to an improvement in study completion and maintenance of weight loss. (Funded by the European Commission; ClinicalTrials.gov number, NCT00390637.).

Eating habits of University students living at, or away from home in Greece

The aim of this study was to assess the effect of living away from, or in, the family home on the dietary habits of a group of Greek undergraduate University students. Eighty-four undergraduates at Athens Agricultural University, aged 20-24, completed a single, self-administered food habits questionnaire that asked about their current food practices and their food practices before they started University. Students living at home did not show major changes in their eating habits since starting University. Although students living away from the family home had made some positive changes, they decreased their weekly consumption of fresh fruit, cooked and raw vegetables, oily fish, seafood, pulses and olive oil, and increased their sugar, wine, alcohol and fast food intake. Between group comparisons of dietary changes showed that since starting University, students living away from home had developed more unfavourable eating habits than students living at the family home. These findings suggest that moving away from the family home and assuming responsibility for food preparation and purchasing for the first time affect dietary habits in this sample of Greek University students. Nutrition interventions in this young population should be encouraged to promote healthier diets and lifestyles, as well as adherence to the traditional Mediterranean diet.

Effects of Weight Loss and Long-Term Weight Maintenance With Diets Varying in Protein and Glycemic Index on Cardiovascular Risk Factors The Diet, Obesity, and Genes (DiOGenes) Study: A Randomized, Controlled Trial

Background— We sought to separately examine the effects of either weight loss or diets varying in protein content and glycemic index without further changes in body weight on cardiovascular risk factors within the Diet, Obesity, and Genes study (DiOGenes). Methods and Results— DiOGenes is a pan-European controlled dietary intervention study in 932 overweight adults who first lost body weight on an 8-week low-calorie diet and were then randomized to 1 of 5 ad libitum diets for 26 weeks. The diets were either high or low protein or high or low glycemic index in 4 combinations or control. Weight loss (−11.23 kg; 95% confidence interval, −11.54 to −10.92; P<0.001) reduced high-sensitivity C-reactive protein (−1.15 mg/L; 95% confidence interval, −1.30 to −0.41; P<0.001), low- and high-density lipoprotein cholesterol, triglycerides, and blood pressure. During the 26-week weight maintenance period in the intention-to-treat analysis, the further decrease of high-sensitivity C-reactive protein blood levels was −0.46 mg/L greater (95% confidence interval, −0.79 to −0.13) in the groups assigned to low-glycemic-index diets than in those on high-glycemic-index diets (P<0.001). Groups on low-protein diets achieved a −0.25 mg/L greater reduction in high-sensitivity C-reactive protein (95% confidence interval, −0.59 to −0.17) than those on high-protein diets (P<0.001), whereas lipid profiles and blood pressure were not differently affected. Conclusions— This large-scale intervention study clearly separates weight loss from dietary composition–related effects. Low-glycemic-index carbohydrates and, to a lesser extent, low-protein intake may specifically reduce low-grade inflammation and associated comorbidities in overweight/obese adults. Clinical Trial Registration— http://www.clinicaltrials.gov. Unique identifier: NCT00390637.

The Effect of Protein and Glycemic Index on Children's Body Composition: The DiOGenes Randomized Study

OBJECTIVE: To investigate the effect of protein and glycemic index (GI) on body composition among European children in the randomized, 6-month dietary intervention DiOGenes (diet, obesity, and genes) family-based study. PATIENTS AND METHODS: In the study, 827 children (381 boys and 446 girls), aged 5 to 18 years, completed baseline examinations. Families with parents who lost ≥8% of their weight during an 8-week run-in low-calorie diet period were randomly assigned to 1 of 5 ad libitum diets: low protein (LP)/low glycemic index (LGI); LP/high GI (HGI); high protein (HP)/LGI; HP/HGI; and control diet. The target difference was 15 GI U between the LGI/HGI groups and 13 protein percentage points between the LP/HP groups. There were 658 children examined after 4 weeks. Advice on food-choice modification was provided at 6 visits during this period. No advice on weight loss was provided because the focus of the study was the ability of the diets to affect outcomes through appetite regulation. Anthropometric measurements and body composition were assessed at baseline, week 4, and week 26. RESULTS: In the study, 465 children (58.1%) completed all assessments. The achieved differences between the GI and protein groups were 2.3 GI U and 4.9 protein percentage points, respectively. The LP/HGI group increased body fat percentage significantly more than the other groups (P = .040; partial η2 = 0.039), and the percentage of overweight/obese children in the HP/LGI group decreased significantly during the intervention (P = .031). CONCLUSIONS: Neither GI nor protein had an isolated effect on body composition. However, the LP/HGI combination increased body fat, whereas the HP/LGI combination was protective against obesity in this sample of children.

The impact on eating habits of temporary translocation from a Mediterranean to a Northern European environment

Objective: To assess the effect of temporary translocation from a Mediterranean to a Northern European environment on the eating habits of a group of foreign students.Design: Cross-sectional survey of eating habits before and after moving from Greece to Glasgow, Scotland.Setting: University of Glasgow.Subjects: Eighty post-graduate Greek students.Interventions: A self-administered questionnaire comprising of three major sections: (1) general eating habits; (2) frequency of eating selected food items; (3) opinion of food availability in Glasgow.Results: After moving to Glasgow, significant decreases were reported in the frequency of consuming fresh fruit, raw vegetables, fish, legumes, meat, poultry and fresh fruit juice. The frequency of eating biscuits, savoury snacks, soft/fizzy drinks, alcoholic drinks and mayonnaise, dips and sauces increased. The estimated median daily consumption of fruit and vegetables decreased from 363u2005g in Greece to just 124u2005g in Glasgow, well below the Scottish and WHO dietary target of 400u2005g/day. The main perceived barriers to maintaining customary eating habits were the price of food, the lack of familiar tastes, the greater availability of convenience food and the limited variety of food available in Glasgow, when compared to Greece.Conclusions: These findings highlight the difficulties that migrant populations face in retaining traditional, often healthier, eating habits when migrating to a foreign country. Barriers of high cost, limited availability and poor quality of familiar foods, need to be addressed in order for migrants to maintain their customary eating patterns. Furthermore, these barriers need to be addressed before nutritionists can expect to see the widespread adoption of the Mediterranean diet by Western populations less familiar with this eating pattern.

The Mediterranean Eating in Scotland Experience project: Evaluation of an Internet-based intervention promoting the Mediterranean diet

A 6-month intervention study with a quasi-experimental design was conducted to evaluate the effectiveness of an Internet-based, stepwise, tailored-feedback intervention promoting four key components of the Mediterranean diet. Fifty-three (intervention group) and nineteen (control group) healthy females were recruited from the Universities of Glasgow and Glasgow Caledonian, Scotland, respectively. Participants in the intervention group received tailored dietary and psychosocial feedback and Internet nutrition education over a 6-month period, while participants in the control group were provided with minimal dietary feedback and general healthy-eating brochures. Internet education was provided via an innovative Mediterranean Eating Website. Dietary changes were assessed with 7 d estimated food diaries at baseline and 6 months, and data were analysed to calculate the Mediterranean Diet Score, a composite score based on the consumption of eight components of the traditional Mediterranean diet. The intention-to-treat analyses showed that, at 6 months, participants in the intervention group had significantly increased their intake of vegetables, fruits and legumes, as well as the MUFA:saturated fatty acid ratio in their diet, and had significantly increased plasma HDL-cholesterol levels and a reduced ratio of total:HDL-cholesterol. Participants in the control group increased their intake of legumes but showed no other favourable significant changes compared with baseline. This Internet-based, tailored-feedback intervention promoting components of the Mediterranean diet holds promise in encouraging a greater consumption of plant foods, as well as increasing monounsaturated fat and decreasing saturated fat in the Scottish diet; it also shows that the Mediterranean diet can be adopted by healthy individuals in northern European countries.

Food and nutrient intake, nutritional knowledge and diet-related attitudes in European adolescents

Background and objective:To provide an overview of methods used to assess food and nutrient intake, nutritional knowledge and diet-related attitudes in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS), with selected results from the feasibility study.Material and Methods:To assess food intake in 13- to 16-year-old adolescents, a previously developed computer-assisted and self-administered 24-h recall was adapted for international use. Food consumption data were linked to national food composition databases to calculate energy and nutrient intakes. To assess nutritional knowledge in pupils not having any special (trained) education concerning ‘nutrition’, a 23-item validated multiple choice questionnaire was adapted. To assess eating attitudes, behaviour and/or putative problems with body weight in adolescents, a validated inventory covering 60 questions or statements was adapted for the study. In a feasibility study, instruments, data collection and processing were tested in one school class in each of the 10 participating European cities.Results and Conclusions:The feasibility study provided plausible results, quite consistent between countries. Against this background and for the first time, standardized and uniform methodology was made available for the main study to assess and characterize dietary intake, nutritional knowledge and eating attitudes.

Developing a methodology for assigning glycaemic index values to foods consumed across Europe

There is growing evidence that the glycaemic index (GI) of the diet is important with respect to body weight and metabolic disease risk. However, research is limited by the paucity of GI values for commonly consumed carbohydrate‐rich foods in European countries. A new methodology has been developed for consistent assignment of GI values to foods across five European databases used in the Diogenes intervention study. GI values were assigned according to five decreasing levels of confidence (1) Measured values for specific foods; (2) Published values from published sources; (3) Equivalent values where published values for similar foods existed; (4) Estimated values assigned as one of three values representing low/medium/high GI ranges and (5) Nominal values assigned as 70, where no other value could be assigned with sufficient confidence. GI values were assigned to 5105 foods. In food records collected at baseline, the contribution to carbohydrate intake of foods assigned levels 1–2 ranged from 16% to 43% depending on country, and this increased to 53–81% including level 3 foods. The degree of confidence to assigned GI values differed across Europe. This standardized approach of assigning GI values will be made available to other researchers to facilitate further investigation into the effects of dietary GI on health.

Nutrition label use mediates the positive relationship between nutrition knowledge and attitudes towards healthy eating with dietary quality among university students in the UK

The aim of this study was to investigate whether nutrition knowledge and attitudes towards healthy eating are predictors of nutrition label use (NLU) and dietary quality in a diverse sample of university students in the UK. An online cross-sectional survey was conducted in 2013 among 500 students (mean age 24.9 years; 75% females) in 37 UK universities. Nutrition knowledge, attitudes, NLU and dietary quality were assessed using previously validated questionnaires. The majority of participants met dietary recommendations for fat, added sugar and fast food intake, and failed to meet recommendations for calcium, fibre, fruit and vegetable and dairy product intake, resulting in a median dietary quality score of 2.0 (score rangeu2009=u20090-8). Nutrition knowledge differed according to gender, age, body mass index (BMI), nationality and NLU. Attitudes towards healthy eating differed according to BMI and NLU and dietary quality differed according to gender. Nutrition knowledge and attitudes were significant predictors of NLU and dietary quality, with NLU mediating the latter relationship, whereas NLU, when controlled for knowledge and attitudes, negatively predicted dietary quality but did not have a significant independent relationship with diet. Future nutrition interventions to improve dietary quality in this sample of UK university students should focus on improving nutrition knowledge and attitudes towards healthy eating.

Fruit and vegetable consumption in a sample of 11-year-old children in ten European countries : the PRO GREENS cross-sectional survey

OBJECTIVEnTo describe fruit and vegetable intake of 11-year-old children in ten European countries and compare it with current dietary guidelines.nnnDESIGNnCross-sectional survey. Intake was assessed using a previously validated questionnaire containing a pre-coded 24 h recall and an FFQ which were completed in the classroom. Portion sizes were calculated using a standardized protocol.nnnSETTINGnSurveys were performed in schools regionally selected in eight countries and nationally representative in two countries.nnnSUBJECTSnA total of 8158 children from 236 schools across Europe participating in the PRO GREENS project.nnnRESULTSnThe total mean consumption of fruit and vegetables was between 220 and 345 g/d in the ten participating countries. Mean intakes did not reach the WHO population goal of ≥400 g/d in any of the participating countries. Girls had a significantly higher intake of total fruit and vegetables than boys in five of the countries (Sweden, Finland, Iceland, Bulgaria and Slovenia). Mean total fruit intake ranged between 114 and 240 g/d and vegetable intake between 73 and 141 g/d. When using the level ≥400 g/d as a cut-off, only 23·5 % (13·8-37·0 %) of the studied children, depending on country and gender, met the WHO recommendation (fruit juice excluded).nnnCONCLUSIONSnFruit and vegetable consumption was below recommended levels among the schoolchildren in all countries and vegetable intake was lower than fruit intake. The survey shows that there is a need for promotional activities to improve fruit and vegetable consumption in this age group.