Ingibjorg Gunnarsdottir

Randomized trial of weight-loss-diets for young adults varying in fish and fish oil content

Objective:To investigate the effect of including seafood and fish oils, as part of an energy-restricted diet, on weight loss in young overweight adults.Design:Randomized controlled trial of energy-restricted diet varying in fish and fish oil content was followed for 8 weeks. Subjects were randomized to one of four groups: (1) control (sunflower oil capsules, no seafood); (2) lean fish (3 × 150 g portions of cod/week); (3) fatty fish (3 × 150 g portions of salmon/week); (4) fish oil (DHA/EPA capsules, no seafood). The macronutrient composition of the diets was similar between the groups and the capsule groups, were single-blinded.Subjects:A total of 324 men and women aged 20–40 years, BMI 27.5–32.5 kg/m2 from Iceland, Spain and Ireland.Measurements:Anthropometric data were collected at baseline, midpoint and endpoint. Confounding factors were accounted for, with linear models, for repeated measures with two-way interactions. The most important interactions for weight loss were (diet × energy intake), (gender × diet) and (gender × initial-weight).Results:An average man in the study (95 kg at baseline receiving 1600 kcal/day) was estimated to lose 3.55 kg (95% CI, 3.14–3.97) (1); 4.35 kg (95% CI, 3.94–4.75) (2); 4.50 kg (95% CI, 4.13–4.87) (3) and 4.96 kg (95% CI, 4.53–5.40) on diet (4) in 4 weeks, from baseline to midpoint. The weight-loss from midpoint to endpoint was 0.45 (0.41–0.49) times the observed weight loss from baseline to midpoint. The diets did not differ in their effect on weight loss in women. Changes in measures of body composition were in line with changes in body weight.Conclusion:In young, overweight men, the inclusion of either lean or fatty fish, or fish oil as part of an energy-restricted diet resulted in ∼1 kg more weight loss after 4 weeks, than did a similar diet without seafood or supplement of marine origin. The addition of seafood to a nutritionally balanced energy-restricted diet may boost weight loss.

Effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile and inflammation markers in metabolic syndrome – a randomized study (SYSDIET)

Different healthy food patterns may modify cardiometabolic risk. We investigated the effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile, blood pressure and inflammatory markers in people with metabolic syndrome.

Dietary macronutrients and food consumption as determinants of long-term weight change in adult populations: a systematic literature review.

This systematic literature review examined the role of dietary macronutrient composition, food consumption and dietary patterns in predicting weight or waist circumference (WC) change, with and without prior weight reduction. The literature search covered year 2000 and onwards. Prospective cohort studies, case–control studies and interventions were included. The studies had adult (18–70 y), mostly Caucasian participants. Out of a total of 1,517 abstracts, 119 full papers were identified as potentially relevant. After a careful scrutiny, 50 papers were quality graded as A (highest), B or C. Forty-three papers with grading A or B were included in evidence grading, which was done separately for all exposure-outcome combinations. The grade of evidence was classified as convincing, probable, suggestive or no conclusion. We found probable evidence for high intake of dietary fibre and nuts predicting less weight gain, and for high intake of meat in predicting more weight gain. Suggestive evidence was found for a protective role against increasing weight from whole grains, cereal fibre, high-fat dairy products and high scores in an index describing a prudent dietary pattern. Likewise, there was suggestive evidence for both fibre and fruit intake in protection against larger increases in WC. Also suggestive evidence was found for high intake of refined grains, and sweets and desserts in predicting more weight gain, and for refined (white) bread and high energy density in predicting larger increases in WC. The results suggested that the proportion of macronutrients in the diet was not important in predicting changes in weight or WC. In contrast, plenty of fibre-rich foods and dairy products, and less refined grains, meat and sugar-rich foods and drinks were associated with less weight gain in prospective cohort studies. The results on the role of dietary macronutrient composition in prevention of weight regain (after prior weight loss) were inconclusive.

Relationship between growth and feeding in infancy and body mass index at the age of 6 years

OBJECTIVE: To assess the relationship between size and growth measurements in infancy to body mass index (BMI) at 6 y.DESIGN: A longitudinal observation study on randomly chosen infants’ growth and consumption in infancy. Follow-up until the age of 6 y.SUBJECTS: A total of 90 children who were born healthy and full-term.MEASUREMENTS: Weight and height were measured at maternity wards and healthcare centers in Iceland throughout infancy and at 6 y. Food records were made every month during infancy. At 2, 4, 6, 9 and 12 months, food was weighed to calculate food and nutrient intake.RESULTS: Weight gain from birth to 12 months as a ratio of birth weight was positively related to BMI at the age of 6 y in both genders (B=2.9±1.0, P=0.008, and B=2.0±0.9, P=0.032 for boys and girls, respectively). Boys in the highest quartile of protein intake (E%) at the age of 9–12 months had significantly higher BMI (17.8±2.4 kg/m2) at 6 y than the lowest (15.6±1.0 kg/m2, P=0.039) and the second lowest (15.3±0.8 kg/m2, P=0.01) quartile. Energy intake was not different between groups. Together, weight gain at 0–12 months and protein intake at 9–12 months explained 50% of the variance in BMI among 6-y-old boys.CONCLUSION: Rapid growth during the first year of life is associated with increased BMI at the age of 6 y in both genders. In boys, high intake of protein in infancy could also contribute to childhood obesity.

Comparison of Women’s Diet Assessed by FFQs and 24-Hour Recalls with and without Underreporters: Associations with Biomarkers

Background/Aims: Women’s diet can be especially difficult to assess, as women tend to underreport their intakes more often than men and are more likely to do so if they think they are overweight or obese. The aim was to compare two methods to assess women’s diet and how well they associate with biomarkers. The influence and frequency of underreporting was also investigated. Methods: Diet of 53 women was assessed by two 24-hour recalls and a food frequency questionnaire (FFQ). Blood was analyzed for retinol, β-carotene, vitamin C and serum ferritin, and 24-hour urine for nitrogen, potassium and sodium. Underreporting was evaluated with nitrogen excretion vs. intake, and energy intake vs. basal metabolic rate. Results: Energy percent (E%) from macronutrients was similar from FFQ and 24-hour recalls, but total intake was higher from 24-hour recalls (9,516 ± 2,080 vs. 8,183 ± 2,893 kJ, p < 0.01). Intakes of vitamin C and potassium from both methods correlated with their respective biomarkers (r = 0.316–0.393). Underreporters had higher body mass index (BMI) than others (27.7 ± 5.5 vs. 23.8 ± 3.7 kg/m2, p < 0.05). They reported lower E% total fat (32 ± 5 vs. 38 ± 6 E%, p < 0.01) and higher E% carbohydrate (49 ± 4 vs. 45 ± 7 E%, p < 0.05). Correlation between intake and biomarkers increased after exclusion of underreporters. Conclusion: For women, FFQ and 24-hour recalls give similar E% and most nutrients correlate, but FFQ gives lower intake. Underreporters have higher BMI and diminish the correlation between calculated intake and biomarkers. This has to be considered when intake data are associated with weight management, disease and lifestyle factors.

Inclusion of fish or fish oil in weight-loss diets for young adults: effects on blood lipids.

Objective:To assess the effects of fish (lean or oily) and fish oil consumption on blood lipid concentration during weight loss.Design:Randomized, controlled 8-week trial of energy-restricted diet varying in fish and fish oil content. Subjects, 324 men and women, aged 20–40 years, body mass index 27.5–32.5 kg m−2, from Iceland, Spain and Ireland, were randomized to one of four groups: (1) control (sunflower oil capsules, no seafood), (2) cod diet (3 × 150 g week−1), (3) salmon diet (3 × 150 g week−1), (4) fish oil (DHA/EPA capsules, no seafood). The macronutrient composition of the diets was similar between the groups and the capsule groups were single-blinded.Measurements:Total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein cholesterol, triacylglycerol (TG) and anthropometrics were measured at baseline and end point.Results:The difference in logTG lowering between the control group and the cod diet, salmon diet and fish oil from baseline to end point was −0.036 (95% CI −0.079 to 0.006), −0.060 (−0.101 to −0.018) and −0.037 (−0.079 to 0.006), respectively. Reduction in TC was about 0.2 mmol l−1 greater in the fish groups (cod and salmon) than in the control group, but only of borderline significance when adjusting for weight loss. HDL tended to decrease less in the diet groups consuming a significant amount of n-3 fatty acids (salmon and fish oil).Conclusion:Weight-loss diet including oily fish resulted in greater TG reduction than did a diet without fish or fish oil. Controlled trials using whole fish as a test meal are encouraged to be able to elucidate the role of different constituents of fish for human health.

Screening Method Evaluated by Nutritional Status Measurements can be Used to Detect Malnourishment in Chronic Obstructive Pulmonary Disease

OBJECTIVE To evaluate and develop a screening method for malnutrition among patients with chronic obstructive pulmonary disease (COPD). DESIGN Findings from a screening sheet for malnutrition were compared with results from full nutritional assessment. The screening sheet included 7 questions regarding body mass index, anorexia, loss of weight, and other variables possibly affecting nutritional status. Each answer was assigned a point value, and a total of 4 and 5 points were tested as criterion for malnutrition. Full nutrition assessment included measurements of weight and height (body mass index), serum albumin and prealbumin, total lymphocyte count, triceps skinfold thickness, mid-arm muscle circumference or area, and information on unintentional weight loss. Malnutrition was defined by 3 or more values below reference values. SUBJECTS Randomly selected patients (n = 34) with a clinical diagnosis of COPD, 15% of eligible patients admitted to the Department of Lung Medicine at National University Hospital, Reykjavik, Iceland, during the time of the study. STATISTICAL ANALYSIS Sensitivity, specificity, and predictive values were calculated to evaluate the screening sheet. Each of the 7 parameters used in a full nutrition assessment was similarly evaluated as an indicator to predict malnutrition. RESULTS Full nutrition assessment identified 13 of 34 patients (38%) as malnourished. Using 4 points as a criterion for malnutrition, the screening sheet to be used for patients with COPD resulted in sensitivity of 0.69 and specificity of 0.90. CONCLUSION The results confirm the frequent finding of malnutrition among patients with COPD and show that a simple screening sheet can be used to identify which patients need further nutrition assessment and treatment.

Assessing validity of a short food frequency questionnaire on present dietary intake of elderly Icelanders

BackgroundFew studies exist on the validity of food frequency questionnaires (FFQs) administered to elderly people. The aim of this study was to assess the validity of a short FFQ on present dietary intake, developed specially for the AGES-Reykjavik Study, which includes 5,764 elderly individuals. Assessing the validity of FFQs is essential before they are used in studies on diet-related disease risk and health outcomes.Method128 healthy elderly participants (74 y ± 5.7; 58.6% female) answered the AGES-FFQ, and subsequently filled out a 3-day weighed food record. Validity of the AGES-FFQ was assessed by comparing its answers to the dietary data obtained from the weighed food records, using Spearmans rank correlation, Chi-Square/Kendalls tau, and a Jonckheere-Terpstra test for trend.ResultFor men a correlation ≥ 0.4 was found for potatoes, fresh fruits, oatmeal/muesli, cakes/cookies, candy, dairy products, milk, pure fruit juice, cod liver oil, coffee, tea and sugar in coffee/tea (r = 0.40-0.71). A lower, but acceptable, correlation was also found for raw vegetables (r = 0.33). The highest correlation for women was found for consumption of rye bread, oatmeal/muesli, raw vegetables, candy, dairy products, milk, pure fruit juice, cod liver oil, coffee and tea (r = 0.40-0.61). An acceptable correlation was also found for fish topping/salad, fresh fruit, blood/liver sausage, whole-wheat bread, and sugar in coffee/tea (r = 0.28-0.37). Questions on meat/fish meals, cooked vegetables and soft drinks did not show a significant correlation to the reference method. Pearson Chi-Square and Kendalls tau showed similar results, as did the Jonckheere-Terpstra trend test.ConclusionA majority of the questions in the AGES-FFQ had an acceptable correlation and may be used to rank individuals according to their level of intake of several important foods/food groups. The AGES-FFQ on present diet may therefore be used to study the relationship between consumption of several specific foods/food groups and various health-related endpoints gathered in the AGES-Reykjavik Study.

Relationship between size at birth and hypertension in a genetically homogeneous population of high birth weight.

Objective To investigate the association between birth size and hypertension within a genetically homogenous population of high birth weight. Design Cohort-study with retrospectively collected data on size at birth. Subjects and setting The study included 4601 men and women born 1914–1935 in Reykjavik, Iceland, who participated in the Reykjavik Study of the Icelandic Heart Association. Main outcome measures Birth size measurements, adult blood pressure (BP) and body mass index (BMI), and family history of hypertension. Results Birth weight was inversely related to hypertension in adulthood in women (P for trend < 0.001). The relationship was of borderline significance in men (P for trend = 0.051). A low ponderal index was significantly associated with high BP in women (P for trend = 0.025) but not men (P > 0.05). For women with an adult BMI > 26 kg/m2, the odds ratio for hypertension for those born weighing < 3.45 kg was 2.1 [95% confidence interval, 1.3–3.3, compared with women born weighing > 3.75 kg. The association was only significant in women without a family history of hypertension. Conclusions An inverse association between size at birth and adult hypertension was seen in a population of greater birth size than has previously been investigated. The relation was strongest among women born small who were overweight in adulthood, and for those without a family history of hypertension. The results support the hypothesis that the association between birth weight and hypertension is not of genetic origin only. The large birth size of Icelanders might be protective and partly explain the lower mean systolic blood pressure in Iceland than in related nations.

Infant weight gain, duration of exclusive breast-feeding and childhood BMI – two similar follow-up cohorts

OBJECTIVE To describe the association between duration of exclusive breast-feeding (EBF), weight gain in infancy and childhood BMI in two populations with a long duration of EBF. DESIGN Cohort study with follow-up in childhood. Breast-feeding status was reported monthly during infancy. Weight and length were measured at birth, 2, 6 and 12 months of age, as well as in childhood at 6 or 10 years of age. SETTING Iceland and Denmark. SUBJECTS Randomly selected healthy newborns from Denmark (n 85) and Iceland (n 100). RESULTS Infants exclusively breast-fed for < or =2 months gained 348 (95% CI 69, 626) g more weight from 2 to 6 months than infants exclusively breast-fed for 3-4 months (P = 0.009). Weight gain from 6 to 12 months was found to be greater among infants exclusively breast-fed for < or =2 months compared with those exclusively breast-fed for > or =5 months (P = 0.008). A greater weight change, in terms of Z-score, between the ages of 2 and 6 months was associated with higher Z-score of childhood BMI, adjusted for birth weight, country and duration of EBF (B = 0.49, se = 0.11, P < 0.001, adj. R2 = 0.15). However, the association was much stronger in the Icelandic cohort than the Danish one. CONCLUSIONS Although duration of EBF was not associated with childhood BMI in the present study it may modulate growth rate in infancy, which is related to childhood BMI. However, other factors determinative for infant growth also need to be considered when assessing the relationship of early growth and nutrition to childhood overweight, as traditions in complementary food might differ between populations.