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1.
Int J Obes (Lond) ; 44(1): 94-103, 2020 01.
Article in English | MEDLINE | ID: mdl-31089262

ABSTRACT

BACKGROUND/OBJECTIVES: Whether variation in sleep and physical activity explain marked ethnic and socioeconomic disparities in childhood obesity is unclear. As time spent in one behaviour influences time spent in other behaviours across the 24-hour day, compositional analyses are essential. The aims of this study were to determine how ethnicity and socioeconomic status influence compositional time use in children, and whether differences in compositional time use explain variation in body mass index (BMI) z-score and obesity prevalence across ethnic groups. METHODS: In all, 690 children (58% European, 20% Maori, 13% Pacific, 9% Asian; 66% low-medium deprivation and 34% high deprivation) aged 6-10 years wore an ActiGraph accelerometer 24-hours a day for 5 days yielding data on sedentary time, sleep, light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA). Height and weight were measured using standard techniques and BMI z-scores calculated. Twenty-four hour movement data were transformed into isometric log-ratio co-ordinates for multivariable regression analysis and effect sizes were back-transformed. RESULTS: European children spent more time asleep (predicted difference in minutes, 95% CI: 16.1, 7.4-24.9) and in MVPA (6.6 min, 2.4-10.4), and less time sedentary (-10.2 min, -19.8 to -0.6) and in LPA (-12.2 min, -21.0 to -3.5) than non-European children. Overall, 10% more sleep was associated with a larger difference in BMI z-score (adjusted difference, 95% CI: -0.13, -0.25 to -0.01) than 10% more MVPA (-0.06, -0.09 to -0.03). Compositional time use explained 35% of the increased risk of obesity in Pacific compared with European children after adjustment for age, sex, deprivation and diet, but only 9% in Maori and 24% in Asian children. CONCLUSIONS: Ethnic differences in compositional time use explain a relatively small proportion of the ethnic differences in obesity prevalence that exist in children.


Subject(s)
Ethnicity/statistics & numerical data , Exercise/physiology , Obesity/epidemiology , Racial Groups/statistics & numerical data , Accelerometry , Child , Cross-Sectional Studies , Female , Humans , Male , Prevalence
2.
Int J Obes (Lond) ; 41(5): 793-800, 2017 05.
Article in English | MEDLINE | ID: mdl-28186099

ABSTRACT

BACKGROUND: To investigate whether changing the play environment in primary schools to one that includes greater risk and challenge increases physical activity and reduces body mass index (BMI). SUBJECTS/METHODS: A 2-year cluster randomised controlled trial was undertaken in 16 New Zealand schools (years 1-8). Intervention schools (n=8) redesigned their play environments to encourage imaginative and independent free play by increasing opportunities for risk and challenge (for example, rough-and-tumble play), reducing rules and adding new playground components (for example, loose parts). Control schools (n=8) were asked to not change their play environment. A qualified playworker rated all school play environments at baseline and 1 year. Primary outcomes were moderate-to-vigorous physical activity (7-day accelerometry) and BMI z-score, collected in 840 children at baseline, 1 and 2 years. Data were analysed using generalised estimating equations. RESULTS: Multiple changes were made to the school play environments resulting in a significant difference in overall play evaluation score between intervention and control schools of 4.50 (95% confidence interval: 1.82 to 7.18, P=0.005), which represents a substantial improvement from baseline values of 19.0 (s.d. 3.2). Overall, schools liked the intervention and reported many benefits, including increased physical activity. However, these beliefs did not translate into significant differences in objectively measured physical activity, either as counts per minute (for example, 35 (-51 to 120) during lunch break) or as minutes of moderate-to-vigorous physical activity (0.4, -1.1 to 2.0). Similarly, no significant differences were observed for BMI, BMI z-score or waist circumference at 1 or 2 years (all P>0.321). CONCLUSIONS: Altering the school play environment to one that promoted greater risk and challenge for children did not increase physical activity, nor subsequently alter body weight. Although schools embraced the concept of adding risk and challenge in the playground, our findings suggest that children may have been involved in different, rather than additional activities.


Subject(s)
Child Behavior , Environment Design , Exercise , Health Promotion/methods , Pediatric Obesity/prevention & control , Play and Playthings , Schools , Accelerometry/instrumentation , Body Mass Index , Body Weight , Child , Cluster Analysis , Environment Design/trends , Female , Humans , Male , New Zealand/epidemiology , School Health Services
3.
Obes Sci Pract ; 1(2): 67-77, 2015 12.
Article in English | MEDLINE | ID: mdl-27774250

ABSTRACT

OBJECTIVE: Non-alcoholic fatty liver disease (NAFLD), defined as excessive fat accumulation in hepatocytes when no other pathologic causes are present, is an increasingly common obesity-related disorder. We sought to describe the prevalence of elevated liver enzymes, a marker of liver damage, among New Zealand adults, and high-risk subgroups including those with an elevated body mass index and those with pre-diabetes or diabetes, to gain a better understanding of the burden of liver disease. METHODS: A total of 4,721 New Zealanders aged 15+ years participated in a nationally representative nutrition survey. Liver enzymes, alanine transaminase (ALT) and gamma glutamyl transpeptidase (GGT) were measured in serum. Results were available for 3,035 participants, of whom 10.8% were Maori and 4.5% Pacific. RESULTS: Overall, the prevalence of elevated ALT and elevated GGT was 13.1% (95% confidence interval [CI]: 11.2 - 15.0) and 13.7% (95% CI: 12.0 - 15.4), respectively. Odds ratios for an elevated ALT or GGT markedly increased with increasing body mass index. Men with obesity had the highest elevated ALT prevalence (28.5%; 95% CI: 21.7-35.4), and women with diabetes had the highest elevated GGT prevalence (36.5%; 95% CI: 26.0-47.0). Adding alcohol consumption categories to each of the adjusted models did not meaningfully change any results, although for women, heavy alcohol consumption was associated with an elevated GGT (overall p = 0.03). CONCLUSIONS: Obesity-related liver disease is likely to increasingly burden the New Zealand health sector and contribute to health disparities unless effective obesity treatment and prevention measures are given high priority. © 2015 The Authors. Obesity Science & Practice published by John Wiley & Sons Ltd, World Obesity and The Obesity Society.

4.
Diabet Med ; 30(3): e101-7, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23181689

ABSTRACT

AIMS: Diabetes rates are especially high in China. Risk of Type 2 diabetes increases with high intakes of white rice, a staple food of Chinese people. Ethnic differences in postprandial glycaemia have been reported. We compared glycaemic responses to glucose and five rice varieties in people of European and Chinese ethnicity and examined possible determinants of ethnic differences in postprandial glycaemia. METHODS: Self-identified Chinese (n = 32) and European (n = 31) healthy volunteers attended on eight occasions for studies following ingestion of glucose and jasmine, basmati, brown, Doongara(®) and parboiled rice. In addition to measuring glycaemic response, we investigated physical activity levels, extent of chewing of rice and salivary α-amylase activity to determine whether these measures explained any differences in postprandial glycaemia. RESULTS: Glycaemic response, measured by incremental area under the glucose curve, was over 60% greater for the five rice varieties (P < 0.001) and 39% greater for glucose (P < 0.004) amongst Chinese compared with Europeans. The calculated glycaemic index was approximately 20% greater for rice varieties other than basmati (P = 0.01 to 0.05). Ethnicity [adjusted risk ratio 1.4 (1.2-1.8) P < 0.001] and rice variety were the only important determinants of incremental area under the glucose curve. CONCLUSIONS: Glycaemic responses following ingestion of glucose and several rice varieties are appreciably greater in Chinese compared with Europeans, suggesting the need to review recommendations regarding dietary carbohydrate amongst rice-eating populations at high risk of diabetes.


Subject(s)
Asian People/ethnology , Glucose/pharmacology , Glycemic Index/physiology , Oryza , Sweetening Agents/pharmacology , White People/ethnology , Adolescent , Adult , Age Distribution , Area Under Curve , Blood Glucose/metabolism , China/ethnology , Female , Glycemic Index/drug effects , Humans , Male , Middle Aged , New Zealand/epidemiology , Postprandial Period/physiology , Young Adult
5.
Diabetologia ; 55(4): 905-14, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22286528

ABSTRACT

AIMS/HYPOTHESIS: To compare the effectiveness of low-fat high-protein and low-fat high-carbohydrate dietary advice on weight loss, using group-based interventions, among overweight people with type 2 diabetes. Study design Multicentre parallel (1:1) design, blinded randomised controlled trial. METHODS: Individuals with type 2 diabetes aged 30­75 years and a BMI >27 kg/m2 were randomised, by an independent statistician using sequentially numbered sealed envelopes, to be prescribed either a low-fat high-protein (30% of energy as protein, 40% as carbohydrate, 30% as fat) or a low-fat high carbohydrate(15% of energy as protein, 55%as carbohydrate,30% as fat) diet. Participants attended 18 group sessions over 12 months. Primary outcomes were change in weight and waist circumference assessed at baseline, 6 and 12 months.Secondary outcomes were body fatness, glycaemic control,lipid profile, blood pressure and renal function. A further assessment was undertaken 12 months after the intervention.Research assessors remained blinded to group allocation throughout. Intention-to-treat analysis was performed. RESULTS: A total of 419 participants were enrolled (mean±SDage 58±9.5 years,BMI 36.6±6.5 kg/m2 and HbA1c 8.1±1.2%(65 mmol/mol)). The study was completed by 70%(294/419).No differences between groups were found in change in weight or waist circumference during the intervention phase or the 12-month follow-up. Both groups had lost weight (2­3 kg, p<0.001) and reduced their waist circumference (2­3 cm, p<0.001) by 12 months and largely maintained this weight loss for the following 12 months. By 6 months, the difference in self-reported dietary protein between groups was small (1.1%total energy; p<0.001). No significant differences between groups were found in secondary outcomes: body fatness, HbA1c, lipids, blood pressure and renal function.There were no important adverse effects. CONCLUSIONS/INTERPRETATION: In a 'real-world' setting, prescription of an energy-reduced low-fat diet, with either increased protein or carbohydrate, results in similar modest losses in weight and waist circumference over 2 years


Subject(s)
Diabetes Mellitus, Type 2/diet therapy , Diet, Reducing , Dietary Carbohydrates , Dietary Proteins , Weight Loss/physiology , Adult , Aged , Blood Pressure/physiology , Body Weight/physiology , Diabetes Mellitus, Type 2/physiopathology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Treatment Outcome
6.
Diabet Med ; 27(10): 1205-8, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20873364

ABSTRACT

OBJECTIVE: To compare postprandial glycaemic responses between Asian and Caucasian subjects. RESEARCH DESIGN AND METHODS: Postprandial capillary blood glucose concentrations were measured as 2-h incremental areas-under-the-curve (iAUCs) following consumption of a glucose beverage and a breakfast cereal in 27 Asians and 73 Caucasians. RESULTS: The mean difference in iAUC was 29%(95%CI 10, 51) and 63%(95%CI 32, 102) higher in the Asian compared with the Caucasian group following the glucose beverage and cereal, respectively.The glycaemic index (GI) of the cereal was 77(95%CI 66, 90) in the Asian group and 61 (95% CI 55, 67) in the Caucasian group; the values were different (P = 0.01). CONCLUSIONS: The findings suggest that dietary recommendations for people with diabetes and those at risk of Type 2 diabetes may be more appropriate if based on research in the ethnic group for which they are intended.


Subject(s)
Asian People/ethnology , Diabetes Mellitus, Type 2/ethnology , Diet/ethnology , Glycemic Index/ethnology , Postprandial Period/physiology , White People/ethnology , Area Under Curve , Diabetes Mellitus, Type 2/physiopathology , Female , Glycemic Index/physiology , Humans , Male , Young Adult
7.
Atherosclerosis ; 211(2): 618-23, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20356595

ABSTRACT

OBJECTIVE: To examine all-cause and cardiovascular mortality in patients with severe hypertriglyceridaemia. METHODS: 337 patients aged less than 80 years (47 with diabetes, 75 women) with a fasting triglyceride concentration on at least two occasions of >5.0mmol/l were registered by 21 lipid clinics in the United Kingdom and followed prospectively between 1980 and 2008 for 4353 person-years. The standardised mortality ratio (SMR) was calculated by comparison with the general population. RESULTS: The mean untreated total cholesterol concentration was 9.8 (SD 3.6)mmol/l for men and 11.9 (7.2)mmol/l for women and the corresponding geometric mean triglyceride concentration was 12.6 (inter-quartile range 7.3, 21.6) and 15.7 (8.2, 29.2)mmol/l. There were 70 deaths, including 35 from CHD and 7 from stroke. The SMR for CHD was raised at 327 (95% confidence intervals 228, 455; p<0.0001) and remained elevated after excluding patients with diabetes at registration (SMR=287, 95% CI 190, 419; p<0.0001), and after excluding patients with CHD at registration (SMR=259, 95% CI 158, 400; p=0.0003). The increased SMR was most marked in younger men aged 40-59 years (SMR=544, 95% CI 304, 897; p<0.0001). The SMR for stroke for patients aged 20-79 years was raised at 262 (95% CI 105, 540; p=0.04), as was all-cause mortality at 164 (95% CI 129, 208; p<0.001). CONCLUSION: Severe hypertriglyceridaemia is associated with a substantially increased mortality from cardiovascular disease, even in the absence of diabetes. In addition to lowering triglyceride concentrations to reduce the risk of pancreatitis, treatment should aim to reduce the overall cardiovascular risk.


Subject(s)
Cardiovascular Diseases/mortality , Hypertriglyceridemia/blood , Adult , Cardiovascular Diseases/epidemiology , Cohort Studies , Coronary Disease/blood , Female , Follow-Up Studies , Humans , Male , Middle Aged , Myocardial Infarction/pathology , Prospective Studies , Registries , Risk , Triglycerides/metabolism
8.
Br J Cancer ; 101(1): 192-7, 2009 Jul 07.
Article in English | MEDLINE | ID: mdl-19536095

ABSTRACT

BACKGROUND: Few prospective studies have examined cancer incidence among vegetarians. METHODS: We studied 61,566 British men and women, comprising 32,403 meat eaters, 8562 non-meat eaters who did eat fish ('fish eaters') and 20,601 vegetarians. After an average follow-up of 12.2 years, there were 3350 incident cancers of which 2204 were among meat eaters, 317 among fish eaters and 829 among vegetarians. Relative risks (RRs) were estimated by Cox regression, stratified by sex and recruitment protocol and adjusted for age, smoking, alcohol, body mass index, physical activity level and, for women only, parity and oral contraceptive use. RESULTS: There was significant heterogeneity in cancer risk between groups for the following four cancer sites: stomach cancer, RRs (compared with meat eaters) of 0.29 (95% CI: 0.07-1.20) in fish eaters and 0.36 (0.16-0.78) in vegetarians, P for heterogeneity=0.007; ovarian cancer, RRs of 0.37 (0.18-0.77) in fish eaters and 0.69 (0.45-1.07) in vegetarians, P for heterogeneity=0.007; bladder cancer, RRs of 0.81 (0.36-1.81) in fish eaters and 0.47 (0.25-0.89) in vegetarians, P for heterogeneity=0.05; and cancers of the lymphatic and haematopoietic tissues, RRs of 0.85 (0.56-1.29) in fish eaters and 0.55 (0.39-0.78) in vegetarians, P for heterogeneity=0.002. The RRs for all malignant neoplasms were 0.82 (0.73-0.93) in fish eaters and 0.88 (0.81-0.96) in vegetarians (P for heterogeneity=0.001). CONCLUSION: The incidence of some cancers may be lower in fish eaters and vegetarians than in meat eaters.


Subject(s)
Diet, Vegetarian , Neoplasms/epidemiology , Adult , Aged , Aged, 80 and over , Animals , Female , Fishes , Humans , Incidence , Male , Meat , Middle Aged , United Kingdom , Young Adult
9.
Nutr Metab Cardiovasc Dis ; 19(3): 226-9, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19282160

ABSTRACT

There is impressive evidence from epidemiological and experimental studies that dietary fibre derived form vegetables, fruit and wholegrain cereals protects against and may be useful in the treatment of a wide range of diseases. However, while there is some evidence of benefit of extracted and synthetic fibres in terms of lowering levels of cardiovascular risk factors, improving measures of glycaemic control and gastrointestinal function, epidemiological confirmation of clinical benefit and long term safety are lacking. An appropriate definition of dietary fibre is essential, given that claiming a food is high in dietary fibre is in effect making a health claim, without formally doing so. The new Codex definition acknowledges the difference between naturally occurring carbohydrate polymers which are neither digested nor absorbed in the human small intestine and synthetic or extracted polymers. However the latter two groups may also be defined as dietary fibre provided "beneficial physiological effect has been demonstrated by generally accepted scientific evidence". Given the need for a definition of dietary fibre which can be used for food labelling, setting nutrient reference values and decisions relating to health claims it is important to achieve agreement as to what constitutes a meaningful physiological effect and the level of evidence required to be certain of such effect.


Subject(s)
Diet Therapy/methods , Dietary Fiber/administration & dosage , Preventive Medicine/methods , Terminology as Topic , Dietary Carbohydrates/administration & dosage , Dietary Fiber/classification , Edible Grain , Fruit , Humans , Vegetables
11.
Open Med Inform J ; 3: 65-76, 2009 Dec 02.
Article in English | MEDLINE | ID: mdl-20148062

ABSTRACT

Insulin sensitivity (SI) estimation has numerous uses in medical and clinical situations. However, highresolution tests that are useful for clinical diagnosis and monitoring are often too intensive, long and costly for regular use. Simpler tests that mitigate these issues are not accurate enough for many clinical diagnostic or monitoring scenarios. The gap between these tests presents an opportunity for new approaches. The quick dynamic insulin sensitivity test (DISTq) utilises the model-based DIST test protocol and a series of population estimates to eliminate the need for insulin or C-peptide assays to enable a high resolution, low-intensity, real-time evaluation of SI. The method predicts patient specific insulin responses to the DIST test protocol with enough accuracy to yield a useful clinical insulin sensitivity metric for monitoring of diabetes therapy. The DISTq method replicated the findings of the fully sampled DIST test without the use of insulin or C-peptide assays. Correlations of the resulting SI values was R=0.91. The method was also compared to the euglycaemic hyperinsulinaemic clamp (EIC) in an in-silico Monte-Carlo analysis and showed a good ability to re-evaluate SI(EIC) (R=0.89), compared to the fully sampled DIST (R=0.98) Population-derived parameter estimates using a-posteriori population-based functions derived from DIST test data enables the simulation of insulin profiles that are sufficiently accurate to estimate SI to a relatively high precision. Thus, costly insulin and C-peptide assays are not necessary to obtain an accurate, but inexpensive, real-time estimate of insulin sensitivity. This estimate has enough resolution for SI prediction and monitoring of response to therapy. In borderline cases, re-evaluation of stored (frozen) blood samples for insulin and C-peptide would enable greater accuracy where necessary, enabling a hierarchy of tests in an economical fashion.

13.
Nutr Metab Cardiovasc Dis ; 18(6): 448-56, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18468872

ABSTRACT

BACKGROUND AND AIM: The recent interest in the development of evidence-based nutrition recommendations has resulted in the development of frameworks which enable a more structured evaluation of the link between diet and chronic disease. This paper examines the application of the frameworks produced by the Scottish Intercollegiate Guidelines Network (SIGN) and the World Cancer Research Fund (WCRF), by using as a case study the association between trans unsaturated fatty acids (TFAs) and coronary heart disease. TFAs arise during industrial hydrogenation of vegetable or fish fats and oils and the natural digestion process in ruminant animals. DATA SYNTHESIS: Numerous studies have examined the effects of TFA intake on serum lipids and lipoproteins and the association between TFA consumption and cardiovascular disease. Metabolic studies and meta-analyses show a clear and consistent association between increasing TFA intakes and an adverse lipid profile. Evidence from case-control and prospective cohort studies examining the association between TFA intakes and coronary heart disease is more heterogeneous and there are limitations in several of the studies. CONCLUSION: While the evidence is sufficient to suggest a probable positive association between TFAs and coronary heart disease, and thus to justify a firm recommendation for a reduction in dietary TFA intake, the evaluation of the data underlines the difficulties in extrapolating the principles of evidence-based medicine to evidence-based nutrition. Furthermore, there is a paucity of research into the effects of animal-derived TFAs in amounts typically consumed in a western diet and their association with adverse lipid profiles or cardiovascular outcomes.


Subject(s)
Cardiovascular Diseases/blood , Cardiovascular Diseases/epidemiology , Evidence-Based Medicine , Trans Fatty Acids/administration & dosage , Trans Fatty Acids/blood , Animals , Cardiovascular Diseases/etiology , Case-Control Studies , Cohort Studies , Coronary Disease/blood , Coronary Disease/epidemiology , Coronary Disease/etiology , Dietary Fats, Unsaturated/administration & dosage , Dietary Fats, Unsaturated/adverse effects , Humans , Risk Factors , Trans Fatty Acids/adverse effects
16.
Int J Obes (Lond) ; 30(2): 342-9, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16158081

ABSTRACT

OBJECTIVE: High-carbohydrate (HC)-high-fibre diets are recommended for weight loss and for treating and preventing diseases such as diabetes and cardiovascular disease. We report a randomised trial comparing high-fat (HF) and high-protein (HP) diets with the conventional approach. RESEARCH DESIGN AND METHODS: A total of 93 overweight insulin-resistant women received advice following randomisation to HF, HP or HC dietary regimes, to achieve weight loss followed by weight maintenance over 12 months. Weight, body composition and measures of carbohydrate and lipid metabolism were investigated. RESULTS: Retention rates were 93% for HP and 75% for HC and HF. Features of the metabolic syndrome improved in all groups during the first 6 months, to a greater extent on HF and HP than an HC. During the second 6 months the HF group had increases in waist circumference (mean difference 4.4 cm (95% CI 3.0, 5.8)), fat mass (2.3 kg (1.5, 3.1)), triglycerides (0.28 mmol/l (0.09, 0.46)) and 2 h glucose (0.70 mmol/l (0.22, 1.18)). Overall there was substantial sustained improvement in waist circumference, triglycerides and insulin in the HP group and sustained but more modest changes on HC. Dietary compliance at 12 months was poor in all groups. CONCLUSIONS: HP and HC approaches appear to be appropriate options for insulin-resistant individuals. When recommending HP diets appropriate composition of dietary fat must be ensured. HC diet recommendations must include advice regarding appropriate high-fibre, low glycaemic index foods.


Subject(s)
Dietary Fats/administration & dosage , Dietary Proteins/administration & dosage , Insulin Resistance , Obesity/diet therapy , Adult , Blood Glucose/analysis , Body Composition , Dietary Carbohydrates/administration & dosage , Dietary Fiber/administration & dosage , Female , Humans , Insulin/blood , Linear Models , Obesity/blood , Time Factors , Treatment Outcome , Triglycerides/blood
17.
Atherosclerosis ; 188(1): 175-8, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16298373

ABSTRACT

Beta-casein is a cow's milk protein that occurs predominantly in two forms, A1 and A2. Epidemiological evidence suggests that per capita consumption of beta-casein A1 is associated with national mortality rates from ischaemic heart disease. A biological mechanism was proposed after rabbits fed diets containing beta-casein A2 had lower serum cholesterol concentrations and less aortic intimal thickening than rabbits fed beta-casein A1. We tested whether beta-casein A1 and A2 variants differentially affect plasma cholesterol concentrations in humans. In a randomised crossover trial of two four-and-a-half week periods without washout, 62 participants replaced all dairy products in their diet with 500 mL of low-fat milk and 28 g of full-fat cheese that differed in the proportion of beta-casein A1 and A2 variants. Duplicate blood samples were taken on non-consecutive days at the end of each treatment period from 55 people who completed the study. Mean (S.D.) plasma total, low-density and high-density lipoprotein cholesterol concentrations were 5.60 (0.77), 3.73 (0.70) and 1.26 (0.34) mmol/L after the A1 diet and 5.63 (0.81), 3.75 (0.75) and 1.27 (0.37) mmol/L after the A2 diets. We found no evidence that dairy products containing beta-casein A1 or A2 exerted differential effects (P > 0.05) on plasma cholesterol concentrations in humans.


Subject(s)
Caseins/administration & dosage , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Diet, Atherogenic , Dietary Proteins/administration & dosage , Milk Proteins/administration & dosage , Adult , Aged , Animals , Caseins/analysis , Dietary Proteins/analysis , Female , Humans , Middle Aged , Milk/chemistry , Milk Proteins/analysis , New Zealand
18.
Diabetologia ; 48(1): 8-16, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15616799

ABSTRACT

AIMS/HYPOTHESIS: A diet low in saturated fatty acids and rich in wholegrains, vegetables and fruit is recommended in order to reduce the risk of obesity, cardiovascular disease and type 2 diabetes mellitus. However there is widespread interest in high-fat ("Atkins Diet") and high-protein ("Zone Diet") alternatives to the conventional high-carbohydrate, high-fibre approach. We report on a randomised trial that compared these two alternative approaches with a conventional diet in overweight insulin-resistant women. METHODS: Ninety-six normoglycaemic, insulin-resistant women (BMI >27 kg/m(2)) were randomised to one of three dietary interventions: a high-carbohydrate, high-fibre (HC) diet, the high-fat (HF) Atkins Diet, or the high-protein (HP) Zone Diet. The experimental approach was designed to mimic what might be achieved in clinical practice: the recommendations involved advice concerning food choices and were not prescriptive in terms of total energy. There were supervised weight loss and weight maintenance phases (8 weeks each), but there was no contact between the research team and the participants during the final 8 weeks of the study. Outcome was assessed in terms of body composition and indicators of cardiovascular and diabetes risk. RESULTS: Body weight, waist circumference, triglycerides and insulin levels decreased with all three diets but, apart from insulin, the reductions were significantly greater in the HF and HP groups than in the HC group. These observations suggest that the popular diets reduced insulin resistance to a greater extent than the standard dietary advice did. When compared with the HC diet, the HF and HP diets were shown to produce significantly (p<0.01) greater reductions in several parameters, including weight loss (HF -2.8 kg, HP -2.7 kg), waist circumference (HF -3.5 cm, HP -2.7 cm) and triglycerides (HF -0.30 mmol/l, HP [corrected] -0.22 mmol/l). LDL cholesterol decreased in individuals on the HC and HP diets, but tended to fluctuate in those on the HF diet to the extent that overall levels were significantly lower in the HP group than in the HF group (-0.28 mmol/l, 95% CI 0.04-0.52, p=0.02). Of those on the HF diet, 25% showed a >10% increase in LDL cholesterol, whereas this occurred in only 13% of subjects on the HC diet and 3% of those on the HP diet. CONCLUSIONS/INTERPRETATION: In routine practice a reduced-carbohydrate, higher protein diet may be the most appropriate overall approach to reducing the risk of cardiovascular disease and type 2 diabetes. To achieve similar benefits on a HC diet, it may be necessary to increase fibre-rich wholegrains, legumes, vegetables and fruits, and to reduce saturated fatty acids to a greater extent than appears to be achieved by implementing current guidelines. The HF approach appears successful for weight loss in the short term, but lipid levels should be monitored. The potential deleterious effects of the diet in the long term remain a concern.


Subject(s)
Diet, Reducing , Dietary Carbohydrates , Dietary Fats , Dietary Proteins , Insulin Resistance/physiology , Obesity/diet therapy , Body Mass Index , Body Size , Calorimetry , Diet, Fat-Restricted , Female , Humans , Lipids/blood , Weight Loss
19.
Eur J Clin Nutr ; 58(11): 1443-61, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15162131

ABSTRACT

This review examines the evidence for the role of whole grain foods and legumes in the aetiology and management of diabetes. MedLine and SilverPlatter ('Nutrition' and 'Food Science FSTA') databases were searched to identify epidemiological and experimental studies relating to the effects of whole grain foods and legumes on indicators of carbohydrate metabolism. Epidemiological studies strongly support the suggestion that high intakes of whole grain foods protect against the development of type II diabetes mellitus (T2DM). People who consume approximately 3 servings per day of whole grain foods are less likely to develop T2DM than low consumers (<3 servings per week) with a risk reduction in the order of 20-30%. The role of legumes in the prevention of diabetes is less clear, possibly because of the relatively low intake of leguminous foods in the populations studied. However, legumes share several qualities with whole grains of potential benefit to glycaemic control including slow release carbohydrate and a high fibre content. A substantial increase in dietary intake of legumes as replacement food for more rapidly digested carbohydrate might therefore be expected to improve glycaemic control and thus reduce incident diabetes. This is consistent with the results of dietary intervention studies that have found improvements in glycaemic control after increasing the dietary intake of whole grain foods, legumes, vegetables and fruit. The benefit has been attributed to an increase in soluble fibre intake. However, prospective studies have found that soluble fibre intake is not associated with a lower incidence of T2DM. On the contrary, it is cereal fibre that is largely insoluble that is associated with a reduced risk of developing T2DM. Despite this, the addition of wheat bran to the diets of diabetic people has not improved indicators of glycaemic control. These apparently contradictory findings might be explained by metabolic studies that have indicated improvement in glucose handling is associated with the intact structure of food. For both grains and legumes, fine grinding disrupts cell structures and renders starch more readily accessible for digestion. The extent to which the intact structure of grains and legumes or the composition of foods in terms of dietary fibre and other constituents contribute to the beneficial effect remains to be quantified. Other mechanisms to help explain improvements in glycaemic control when consuming whole grains and legumes relate to cooking, type of starch, satiety and nutrient retention. Thus, there is strong evidence to suggest that eating a variety of whole grain foods and legumes is beneficial in the prevention and management of diabetes. This is compatible with advice from around the world that recommends consumption of a wide range of carbohydrate foods from cereals, vegetables, legumes and fruits both for the general population and for people with diabetes.


Subject(s)
Diabetes Mellitus, Type 2/etiology , Diabetes Mellitus, Type 2/prevention & control , Dietary Fiber/administration & dosage , Edible Grain , Fabaceae , Blood Glucose/drug effects , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/epidemiology , Dietary Fiber/metabolism , Edible Grain/chemistry , Epidemiologic Studies , Fabaceae/chemistry , Fruit , Humans , Prospective Studies , Risk Factors , Solubility , Vegetables
20.
Br J Cancer ; 90(1): 118-21, 2004 Jan 12.
Article in English | MEDLINE | ID: mdl-14710217

ABSTRACT

In a cohort of 10 998 men and women, 95 incident cases of colorectal cancer were recorded after 17 years. Risk increased in association with smoking, alcohol, and white bread consumption, and decreased with frequent consumption of fruit. The relative risk in vegetarians compared with nonvegetarians was 0.85 (95% CI: 0.55-1.32).


Subject(s)
Colorectal Neoplasms/epidemiology , Colorectal Neoplasms/etiology , Diet, Vegetarian , Life Style , Adult , Alcohol Drinking/adverse effects , Cohort Studies , Epidemiologic Studies , Female , Fruit , Humans , Incidence , Male , Nutritional Status , Risk Factors , Smoking/adverse effects , United Kingdom/epidemiology
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