Jimmy Chun Yu Louie

Association between intake of total vs added sugar on diet quality: a systematic review

CONTEXTnGiven its potential effect on nutrient and energy density, the sugar content of the diet is a subject of controversy.nnnOBJECTIVEnThe aim of this review was to examine the cross-sectional or prospective evidence for associations between the intake of total sugar or added sugar (high vs low intakes) and diet quality or nutrient intakes in the general population.nnnDATA SOURCESnThe following databases were searched for English-language articles published between 1972 and 2012: CINAHL Plus, EBM Reviews, ERIC, MEDLINE, PREMEDLINE, PsycINFO, PubMed, and ScienceDirect.nnnSTUDY SELECTIONnThe search identified studies that examined the association between intake of total sugar and/or added sugar and diet quality (nu2009=u200922) or nutrient intakes (nu2009=u200930).nnnDATA EXTRACTIONnThe following data were extracted: sample size and population, dietary assessment method, source of added sugar data, source of funding, comparator, association between total sugar or added sugar and diet quality, and the direction and magnitude of the association.nnnDATA SYNTHESISnOf 22 studies, all except 1 found a higher intake of added sugar to be associated with poorer diet quality, and the exceptional study did not adjust for total energy intake. Twenty-one of 30 studies found a negative association between added sugar and micronutrient intakes. The same association was not found for total sugar intake.nnnCONCLUSIONnAny negative association between dietary sugar and diet quality is better exposed by referring to added sugar rather than total sugar. There was substantial variation in features of study quality, including sample size, so the magnitude of the observed effect was generally small and may not be of clinical significance. Furthermore, the positive influence that core foods such as fruit and milk exert on total sugar values may bias the association between total sugar and diet quality.

Dairy food consumption, blood pressure and retinal microcirculation in adolescents

BACKGROUND AND AIMSnThe relationship between dairy food consumption and dietary calcium intake, and vascular risk factors during adolescence remains unclear. We aimed to prospectively assess whether dairy food consumption (milk, cheese, yoghurt) is associated with blood pressure (BP) and retinal microvascular signs among adolescents.nnnMETHODS AND RESULTSnAs many as 2353 and 1216 participants aged 12 and 17, respectively, were examined. Longitudinal analyses involved 888 subjects with complete baseline and follow-up data. Dairy consumption was assessed from validated semi-quantitative food frequency questionnaires. BP information was collected and retinal vessel caliber was quantified from digital photographs using computer software. In girls, after multivariable adjustment, each serve/day increase in total dairy intake was concurrently associated with 1.04 (p = 0.03) and 1.10 mm Hg (p = 0.02) decreases in mean diastolic and arterial BP, respectively. Also in girls, each serve/day increase in cheese intake over 5 years was concurrently related to 7.18 (p = 0.001), 5.28 (p = 0.002) and 5.79 mm Hg (p = 0.001) decrease in mean systolic, diastolic and arterial BP, respectively. Among girls, each 100 mg/day increase in dietary calcium intake was associated with a concurrent 0.5 (p = 0.01) and 0.3 mm Hg (p = 0.02) decrease in mean systolic and arterial BP, respectively. Cross-sectionally, adolescents in the highest versus lowest tertile of yoghurt intake had ∼ 1.3 μm wider retinal arterioles (p = 0.05) and ∼ 2.0 μm narrower venules (p = 0.04).nnnCONCLUSIONSnConsumption of dairy products, particularly cheese, could have a beneficial effect on BP, particularly among girls.

Carbohydrates, glycemic index, and pregnancy outcomes in gestational diabetes

This review critically evaluates the current evidence regarding the effect of the dietary glycemic index (GI) on pregnancy outcomes in gestational diabetes mellitus (GDM). Current evidence, although limited, consistently supports the advantages of, and has demonstrated no disadvantages of, a low-GI diet. We conclude that pregnant women with GDM are likely to benefit from following a low-GI meal pattern, with no significant side effects, and consideration of the GI should be given when formulating a diet for GDM. However, until larger scale intervention trials are completed, an exclusive low-GI diet should not replace the current recommended diets for GDM from relevant government and health agencies. Further studies that intervene at an earlier stage of pregnancy are required.

Foods, nutrients or whole diets: effects of targeting fish and LCn3PUFA consumption in a 12mo weight loss trial

BackgroundThere is some evidence in the literature that emphasising fish consumption may assist with weight loss. The aim was to assess the effects of advice to consume 2 fish meals per week in a weight loss diet.MethodsA parallel randomised placebo-controlled trial was conducted in 118 obese Australian adults (mean BMIu2009±u2009SD 31.3u2009±u20093.5xa0kg/m2; mean ageu2009±u2009SD 45u2009±u200910 y; 28% male). Participants received low calorie dietary adviceu2009+u2009placebo (1xa0g olive oil; Control), low calorie dietary advice emphasising fishu2009+u2009placebo (Fish), or low calorie dietary advice emphasising fish dietu2009+u2009LCn3PUFA supplements (Fishu2009+u2009S). Individualised advice targeted 2xa0MJ energy deficit (30%E fat, 45%E carbohydrate and 25%E protein) with or without two servings (180xa0g) fatty fish/wk.ResultsAll groups lost weight at 12xa0months (Control −4.5xa0kg vs. Fish −4.3xa0kg vs. Fishu2009+u2009S −3.3xa0kg; pu2009<u20090.001) and percentage body fat (Control: -1.5% vs. Fish: -1.4% vs. Fishu2009+u2009S: -0.7%; pu2009<u20090.001) but there were no significant differences between groups. Cardiovascular disease risk factors changed as expected from weight loss.ConclusionsAdvice to consume 2 fish meals per week did not enhance the effects on weight loss of a healthy low calorie diet.Trial registrationACTRN12608000425392.

Consumption of dairy products and the 15-year incidence of age-related macular degeneration

Habitual consumption of dairy products has been shown to play an important role in the prevention of several chronic diseases. We aimed to prospectively assess the relationship between the change in dairy product consumption (both regular fat and low/reduced fat) and the 15-year incidence of age-related macular degeneration (AMD). In the Blue Mountains Eye Study, 2037 participants aged 49 years or above at baseline were re-examined at follow-up in 1997-9, 2002-4 and/or 2007-9. AMD was assessed from retinal photographs. Dietary data were collected using a semi-quantitative FFQ, and servings of dairy product consumption calculated. Over the 15-year follow-up, there were 352, 268 and eighty-four incident cases of any, early and late AMD, respectively. After adjusting for age, sex, current smoking, white cell count and fish consumption, a significant linear trend (P for trendxa0=xa00·003) was observed with decreasing consumption of total dairy foods and the 15-year incidence of late AMD, comparing the lowest v. highest quintile of intake (OR 2·80, 95xa0% CI 1·21, 3·04). Over the 15 years, decreased consumption of reduced-fat dairy foods was associated with an increased risk of incident late AMD, comparing the lowest to highest quintile of intake (OR 3·10, 95xa0% CI 1·18, 8·14, P for trendxa0=xa00·04). Decreasing total dietary Ca intake over the 15 years was also associated with an increased risk of developing incident late AMD (multivariable-adjusted P for trendxa0=xa00·03). A lower consumption of dairy products (regular and low fat) and Ca was independently associated with a higher risk of developing incident late AMD in the long term. Additional cohort studies are needed to confirm these findings.

Dietary glycemic load, insulin load, and weight loss in obese, insulin resistant adolescents: RESIST study

BACKGROUND & AIMSnThe optimal dietary approach for weight loss and improving insulin sensitivity in adolescents is unknown. This study aimed to explore the association between the estimated insulin demand of the diet, as measured by glycemic and insulin load, weight loss, percentage body fat and insulin sensitivity index (ISI) in obese adolescents with clinical features of insulin resistance and/or prediabetes after a 3 month lifestyle and metformin intervention.nnnMETHODSnSecondary data analysis of 91 adolescents (median age 12.7 years (range 10.1-17.4) participating in a randomized controlled trial, known as RESIST; ACTRN12608000416392. Weight change between baseline and 3 months was measured by BMI expressed as percentage of the 95th centile (BMI %95). Body composition was measured by dual energy X-ray absorptiometry and ISI was determined by an oral glucose tolerance test.nnnRESULTSnHigher dietary glycemic load and insulin load were associated with less weight loss (BMI %95), adjusted for sex and pubertal stage, β = 0.0466, P = 0.007 and β = 0.0124, P = 0.040, respectively. Inclusion of total energy intake in the model explained observed associations between dietary glycemic load and insulin load and change in BMI %95. Neither dietary glycemic load nor insulin load were associated with changes in percentage body fat or ISI. Dietary glycemic index and macronutrient content (% of total energy) were not associated to changes in BMI %95, percentage body fat or ISI.nnnCONCLUSIONnReduced energy diet contributes to weight loss in obese, insulin resistant adolescents. Diets with a lower insulin demand were associated with a lower energy intake and may hence assist with weight loss.

Intake of total and added sugars and nutrient dilution in Australian children and adolescents

This analysis aimed to examine the association between intake of sugars (total or added) and nutrient intake with data from a recent Australian national nutrition survey, the 2007 Australian National Childrens Nutrition and Physical Activity Survey (2007ANCNPAS). Data from participants (n 4140; 51 % male) who provided 2×plausible 24-h recalls were included in the analysis. The values on added sugars for foods were estimated using a previously published ten-step systematic methodology. Reported intakes of nutrients and foods defined in the 2007ANCNPAS were analysed by age- and sex-specific quintiles of %energy from added sugars (%EAS) or %energy from total sugars (%ETS) using ANCOVA. Linear trends across the quintiles were examined using multiple linear regression. Logistic regression analysis was used to calculate the OR of not meeting a specified nutrient reference values for Australia and New Zealand per unit in %EAS or %ETS. Analyses were adjusted for age, sex, BMI z-score and total energy intake. Small but significant negative associations were seen between %EAS and the intakes of most nutrient intakes (all P<0·001). For %ETS the associations with nutrient intakes were inconsistent; even then they were smaller than that for %EAS. In general, higher intakes of added sugars were associated with lower intakes of most nutrient-rich, core food groups and higher intakes of energy-dense, nutrient-poor extra foods. In conclusion, assessing intakes of added sugars may be a better approach for addressing issues of diet quality compared with intakes of total sugars.

Nutrition for a Healthy Pregnancy Lessons for Obesity

According to conventional wisdom, nutritional requirements increase dramatically during pregnancy due to the rapid growth of the fetus. Adequate nutrition is therefore paramount to a healthy pregnancy. On the other hand, there are several foodrelated risks that may hinder the ability of a pregnant woman to choose a wide variety of foods and achieve sufficient nutrition. Media coverage of diet in pregnancy has also tended to create confusion for both the public and health professionals. Fortunately, Harvey and Ricciotti, in this issue of American Journal of Lifestyle Medicine, provide a clear, up-to-date, and comprehensive review of various nutrition-related issues faced by pregnant women. They begin with an overview of one of the biggest public health issues of the century that also has critical ramifications for pregnancy—obesity. Overweight and obesity rates around the world have remained high and show no sign of declining, meaning many women will be overweight or obese prior to conception. An overweight or obese mother-to-be has a much higher risk of developing complications such as preeclampsia and gestational diabetes mellitus (GDM). Her offspring have a 2to 3-fold increased risk of being overweight and obese even as children, thereby creating a vicious cycle. If we are to make any progress in the war against obesity, interventions must begin before conception. It is not uncommon for women of normal weight prior to pregnancy to gain excessive weight during pregnancy. This may be partly due to current dietary guidelines for pregnancy and the widespread belief (even among health professionals) that women need to eat significantly more to provide adequate energy for the growth of the fetus. Theoretically, the total energy