Dietary quality in people with type 1 and type 2 diabetes compared to age, sex and BMI matched controls

Dietary changes based on food purchase patterns following a type 2 diabetes diagnosis

OBJECTIVE

The study explores whether type 2 diabetes (T2D) diagnosis affects food consumption patterns in line with the dietary recommendations provided to individuals in relation to a diagnosis.

DESIGN

Based on detailed food purchase data, we explore which dietary changes are most common following a T2D diagnosis. Changes are investigated for several energy-adjusted nutrients and food groups and overall adherence to dietary guidelines.

SETTING

We use data on diagnosis of T2D and hospitalisation in relation to T2D for a sample of adult Danes registered in the official patient register. This is combined with detailed scanner data on food purchases, which are used as a proxy for dietary intake.

PARTICIPANTS

We included 274 individuals in Denmark who are diagnosed during their participation in a consumer panel where they report their food purchases and 16 395 individuals who are not diagnosed.

RESULTS

Results suggest some changes in dietary composition following diagnosis, as measured by a Healthy Eating Index and for specific food groups and nutrients, although the long-term effects are limited. Socio-economic characteristics are poor predictors of dietary changes following diagnosis. Change in diet following diagnosis vary with the pre-diagnosis consumption patterns, where individuals with relatively unhealthy overall diets prior to diagnosis improve overall healthiness more compared to individuals with relatively healthy diets prior to diagnosis.

CONCLUSIONS

Adherence to dietary advice is low, on average, but there is large variation in behavioural change between the diagnosed individuals. Our results stress the difficulty for diagnosed individuals to shift dietary habits, particularly in the long term.

Dietary Glycaemic Index Labelling: A Global Perspective

The glycaemic index (GI) is a food metric that ranks the acute impact of available (digestible) carbohydrates on blood glucose. At present, few countries regulate the inclusion of GI on food labels even though the information may assist consumers to manage blood glucose levels. Australia and New Zealand regulate GI claims as nutrition content claims and also recognize the GI Foundation’s certified Low GI trademark as an endorsement. The GI Foundation of South Africa endorses foods with low, medium and high GI symbols. In Asia, Singapore’s Healthier Choice Symbol has specific provisions for low GI claims. Low GI claims are also permitted on food labels in India. In China, there are no national regulations specific to GI; however, voluntary claims are permitted. In the USA, GI claims are not specifically regulated but are permitted, as they are deemed to fall under general food-labelling provisions. In Canada and the European Union, GI claims are not legal under current food law. Inconsistences in food regulation around the world undermine consumer and health professional confidence and call for harmonization. Global provisions for GI claims/endorsements in food standard codes would be in the best interests of people with diabetes and those at risk.

Diet Quality Indices Used in Australian and New Zealand Adults: A Systematic Review and Critical Appraisal

Distilling the complexity of overall diet into a simple measure or summative score by data reduction methods has become a common practice in nutritional epidemiology. Recent reviews on diet quality indices (DQI) have highlighted the importance of sound construction criteria and validation. The aim of this current review was to identify and critically appraise all DQI used within Australian and New Zealand adult populations. Twenty-five existing DQI were identified by electronic searching in Medline and hand searching of reference lists. DQI were constructed based on the respective national dietary guidelines and condition-specific recommendations. For preferable features of DQI, six captured the dimensions of adequacy, moderation and balance; five had a nested structure; 12 consisted of foods, food groups and nutrients; 11 used metric scoring systems and most of those with metric scales used normative cutoff points. Food frequency questionnaires, either alone or with other methods, were the most common dietary assessment method used in 20 DQI. For evaluation of DQI, construct validity and relative validity are reported. Based on our critical appraisal, Dietary Guideline Index (DGI), Dietary Guideline Index-2013 (DGI-2013), Total Diet Score (TDS), Healthy Eating Index for Australian Adults-2013 (HEIFA-2013), and Aussie-Diet Quality Index (Aussie-DQI) were the preferred DQI used in Australian adults according to dimension, indicator selection, scoring criteria and evaluation. Further work is needed to enhance the construction of all Australian and New Zealand DQI, especially in terms of dimension and structure, for alignment with recommended construction criteria.

Australian children with type 1 diabetes consume high sodium and high saturated fat diets: Comparison with national and international guidelines

AIM

We aimed to evaluate the diets of children with type 1 diabetes (T1D) against recommended Australian dietary intakes and international T1D guidelines and compare them to children without T1D.

METHODS

A cross-sectional analysis in 143 children (103 children aged 8-18 years with T1D and 40 age- and gender-matched controls) and longitudinal analysis at 0, 3, 6 and 12 months in 90 T1D children were conducted. Diet was assessed using an Australian validated food frequency questionnaire. Diet quality was assessed against recommended servings and nutrient intakes from Australian Dietary Guidelines and International Society for Pediatric and Adolescent Diabetes (ISPAD) Nutritional Guidelines.

RESULTS

Diet was evaluated in 478 questionnaires. Diet composition did not differ between T1D and controls, and both groups did not meet the majority of the Australian Dietary Guidelines, except for fruit intake. The majority of T1D children and controls (80-83%) were overconsuming sodium (2837 ± 848 mg/day), discretionary foods (5.9 ± 2.5 serves/day) and saturated fat and trans fatty acids (13.1 ± 2.7% of total daily energy intake) in comparison with Australian and ISPAD guidelines. A total of 84% of T1D children and controls achieved the recommended intake of fibre (34.4 ± 11.0 g/day). Longitudinal analysis in children with T1D showed that total daily energy, macronutrient, micronutrient and food group servings intake did not change over the 12 months. Overconsumption of sodium, discretionary foods and saturated fat persisted over the 12-month study period.

CONCLUSIONS

The majority of Australian children, with and without T1D, is not meeting recommended dietary guidelines. Significant overconsumption of sodium, saturated fat and discretionary foods attracts the most concern.

A High-Fiber Diet Decreases Postabsorptive Protein Turnover but Does Not Alter Insulin Sensitivity in Men with Type 1 Diabetes Mellitus

BACKGROUND

High-fiber diets (HFDs) are recommended in the diet of persons with diabetes, yet such diets can impair macronutrient digestion and/or absorption, modify insulin sensitivity, and reset metabolism.

OBJECTIVES

We studied the effects of a HFD on the kinetics of whole-body protein, a macronutrient that could be affected by dietary fiber, in type 1 diabetes mellitus (T1DM), under both basal-low insulinemic and hyperinsulinemic conditions.

METHODS

Eight men with T1DM (body mass index range: 21.8-27.8 kg/m2) were studied twice - before and after the addition of guar gum (∼15 g/d) to their usual diet for ∼4 mo. Whole-body protein degradation (i.e., the rate of appearance [Ra] of endogenous leucine), leucine disposal to protein synthesis (PS), deamination, and reamination, were determined before and after the HFD, both in the postabsorptive state and following a euglycemic, hyperinsulinemic, hyperaminoacidemic clamp, using isotope dilution methods.

RESULTS

After the HFD, mean values (± SEs) for postabsorptive leucine Ra decreased by ∼20%: from 2.52 (0.15) to 2.03 (0.16) μmol x kg-1 x min-1, P < 0.049, after vs. before the HFD respectively. PS also decreased, by ∼25%: from 2.03 (0.15) to 1.57 (0.15), P < 0.045. Leucine concentration (P = 0.1) and reamination (P = 0.095) decreased moderately, whereas deamination was unchanged. Following the clamp, plasma amino acid concentrations (P < 0.001), leucine deamination (+ ∼50%, P < 0.00002), reamination (+ ∼30%, P < 0.0007), and PS (+ ∼35%, P < 0.00001) were all increased compared with postabsorptive state values, whereas endogenous leucine Ra was suppressed (by 15%, P < 0.00001, and by 25%, P < 0.001, with the primary or the reciprocal pool models, respectively). No significant differences in these insulin effects before compared with after the HFD were observed. Metabolic control (glycated hemoglobin), daily insulin requirement, and insulin-mediated glucose disposal were unchanged after the HFD.

CONCLUSIONS

A HFD downregulates postabsorptive protein turnover in men with T1DM, by decreasing both protein degradation and synthesis, possibly due to a subtle decrease and/or delay in amino acid absorption. It does not significantly affect the insulin (and amino acid sensitivity) to protein turnover, glucose disposal, and metabolic control.

Dietary habits and adherence to dietary recommendations in patients with type 1 and type 2 diabetes compared with the general population in Denmark

OBJECTIVES

The aim of the present study was to examine dietary habits and adherence to dietary recommendations in adult patients with type 1 diabetes (T1D) and type 2 diabetes (T2D) compared with the general population in Denmark.

METHODS

The study was cross-sectional and included 426 patients with T1D and 348 patients with T2D recruited from an outpatient diabetes clinic in the capital region of Denmark. Dietary habits were assessed by a food frequency questionnaire and compared with dietary data from 2,899 participants without diabetes from the Danish National Survey of Dietary Habits and Physical Activity.

RESULTS

Patients with diabetes had a 20-50% lower intake of added sugar and alcohol, and a 10-20% higher intake of fibre and vegetables compared with the general population (p<0.001 for all). Patients with T2D had a 37% lower intake of alcohol compared with T1D (p<0.001). Adherence to dietary recommendations (e.g. fibre, saturated fat, vegetables, fruit and fish) were low in all groups but lowest in the general population.

CONCLUSION

The Danish diet is too high in saturated fat and too low in dietary fibre, vegetable, fruit and fish compared to dietary recommendations in both patients with diabetes and the general population. However, our data demonstrate that patients with diabetes consume a healthier diet compared to the general population: Limiting the intake of added sugar and alcohol, and increasing the intake of vegetables and dietary fibre.

Dietary quality and carotid intima media thickness in type 1 and type 2 diabetes: Follow-up of a randomised controlled trial

BACKGROUND AND AIMS

The relationship between dietary intake and carotid intima media thickness (IMT) and pulse wave velocity (PWV) in individuals with type 1 and type 2 diabetes has not been well studied. We investigated the association between dietary intake and common carotid artery intima media thickness (CCA IMT) and PWV in a cohort with type 1 and type 2 diabetes.

METHODS AND RESULTS

A one-year randomised controlled trial was conducted to investigate the effect of improving dietary quality on CCA IMT. These subjects were followed up again approximately 12 months after the completion of the trial (i.e. approximately 24 month since baseline). The study cohort included 87 subjects that had dietary intake and CCA IMT measured at baseline and after a mean of 2.3 years' follow-up. PWV was measured in a subsample of this cohort. Age and baseline mean CCA IMT were strongly associated with mean CCA IMT at 24 months. After adjustment for age and baseline mean CCA IMT, baseline consumption of carbohydrate (r = -0.28; p = 0.01), sugars (r = -0.27; p = 0.01), fibre (r = -0.26; p = 0.02), magnesium (r = -0.25; p = 0.02) and the Alternate Health Eating Index (AHEI) score (r = -0.23; p = 0.03) were inversely associated with mean CCA IMT at 24 months. Mixed linear modelling showed an interaction between mean CCA IMT and AHEI at baseline (p = 0.024). Those who were in the highest AHEI tertile at baseline had greater CCA IMT regression at 24 months compared to those in the lowest tertile, after adjustment for baseline age, BMI, smoking pack years, time since diabetes diagnosis, and mean arterial pressure at baseline (mean -0.043 mm; 95% CI -0.084, -0.003; p = 0.029).

CONCLUSIONS

In this prospective analysis greater diet quality at baseline, as measured by the AHEI, was associated with greater CCA IMT regression after approximately two years. This suggests that greater diet quality is associated with better longer term vascular health in individuals with type 1 and type 2 diabetes.

Effect of Improving Dietary Quality on Arterial Stiffness in Subjects with Type 1 and Type 2 Diabetes: A 12 Months Randomised Controlled Trial

People with diabetes have accelerated arterial stiffening. The aim of this study was to determine the effect of increasing fruit, vegetable and dairy intake for 12 months on carotid femoral pulse wave velocity (cfPWV), augmentation index (AIx), and central blood pressure (cBP), compared to a usual diet control, in people with type 1 and type 2 diabetes. In a 12 months randomised controlled trial, cfPWV, AIx and cBP were measured every 3 months. The intervention group received dietary counselling to increase consumption of fruit (+1 serving/day; 150 g/day), vegetables (+2 servings/day; 150 g/day) and dairy (+1 serving/day; 200–250 g/day) at baseline, 1, 3, 6 and 9 months. The control group continued on their usual diet. One hundred and nine participants were randomised and 92 (intervention n = 45; control n = 47) completed. At 3 months, fruit (184 g/day; p = 0.001) and dairy (83 g/day; p = 0.037) intake increased in the intervention group compared with the control group but this increase was not maintained at 12 months. After adjustment for baseline measurements there was no time by treatment effect for central systolic or diastolic BP, AIx or cfPWV. A time effect existed for AIx which modestly increased over time. Peripheral diastolic BP and central pulse pressure were improved in the intervention group compared with the control group at 12 months. In the cohort with type 1 and type 2 diabetes, improving dietary quality by increasing consumption of fruit, vegetables and dairy did not improve cBP, AIx or cfPWV, compared with a control group continuing on their usual diet, after 12 months.

Effect of improving dietary quality on carotid intima media thickness in subjects with type 1 and type 2 diabetes: a 12-mo randomized controlled trial

BACKGROUND

People with diabetes are at a heightened risk of cardiovascular disease compared with the general population. To our knowledge, randomized controlled trials investigating the effect of improving dietary quality on carotid intima media thickness, a marker of subclinical atherosclerosis and predictor of cardiovascular disease, have not been conducted in populations with diabetes.

OBJECTIVE

We aimed to determine whether increasing fruit (+1 serving; 150 g/d), vegetable (+2 servings; 150 g/d), and dairy (+1 serving; 200-250 g/d) intakes slows 12-mo common carotid artery intima media thickness (CCA IMT) progression, compared with a control group continuing to consume their usual diet, in people with type 1 and type 2 diabetes.

DESIGN

A 12-mo randomized controlled trial was conducted. The primary outcome was mean CCA IMT, measured at baseline and 12 mo, with B-mode ultrasound. Participants in the intervention group received counseling from a dietitian at baseline and 1, 3, 6, and 9 mo, and compliance was measured with a food-frequency questionnaire at baseline, 3 mo, and 12 mo. The control group continued consuming their usual diet.

RESULTS

In total, 118 participants completed the study. Vegetable (46 g/d; 95% CI: 14, 77 g/d; P < 0.001) and fruit (179 g/d; 95% CI: 119, 239 g/d; P < 0.001) intakes were increased at 3 mo in the intervention group compared with the control group. This increase was not maintained at 12 mo, but intake increased overall in the cohort (fruit, 48 g/d; vegetables, 14 g/d). An increase in dairy consumption was not achieved, but yogurt intake was higher in the intervention group at 3 mo (38 g; 95% CI: 12, 65 g; P < 0.001); this was not maintained at 12 mo. At 12 mo, CCA IMT regressed (mean ± SD: -0.01 ± 0.04 mm; P < 0.001), with a greater effect in the treatment group (mean ± SD: -0.02 ± 0.04 mm compared with -0.004 ± 0.04 mm; P = 0.009).

CONCLUSION

Improving dietary quality in people with well-controlled type 1 and type 2 diabetes may slow CCA IMT progression. This trial was registered at https://www.anzctr.org.au as ACTRN12613000251729.

Salt Restriction in Diabetes

There are no long-term interventions examining the effects of salt reduction in people with diabetes, and these are urgently required. Sodium reduction is controversial as it appears that an intake below 2.5 g and above 6 g/day of salt is associated with increased cardiovascular disease risk. However, pre-existing illness leading to a lower salt intake may confound the findings. Only a few studies have prospectively collected data on the sodium intake and excretion of people with diabetes and examined hard end points. In addition, future studies need to collect more data on food intake as well as coexistent illnesses to address potential confounding. The World Health Organization recommends a reduction to less than 5 g/day salt in adults. Given that the available evidence suggests that the salt intake of people with type 2 diabetes is generally well above 6 g/day it seems reasonable to ensure individuals with diabetes have an intake below 6 g/day. However, such recommendations need to be individualized.