Effects of very low-carbohydrate vs. high-carbohydrate weight loss diets on psychological health in adults with obesity and type 2 diabetes: a 2-year randomized controlled trial.

AIMS: Very low-carbohydrate (LC) diets are popular for type 2 diabetes (T2DM) management; however, long-term effects on psychological health remain largely unknown. This study reports the effects of a LC diet on mood and cognitive function after 2 years and explores the potential predictors of changes in psychological health. METHODS: 115 adults (57% males; age: 58.5 ± 7.1 years) with obesity and T2DM were randomized to consume an energy reduced (~ 500 to 1000 kcal/day deficit), LC diet [14% energy as carbohydrate, 28% protein, 58% fat (< 10% saturated fat)] or an isocaloric high unrefined carbohydrate, low-fat diet [HC: 53% carbohydrate, 17% protein, 30% fat (< 10% saturated fat)] for 2 years. Both diets were combined with aerobic/resistance exercise (1 h, 3 days/week). Mood/well-being [Beck Depression Inventory (BDI), Spielberger State Anxiety Inventory (SAI), Profile of Mood States (POMS)], diabetes-related quality of life [Diabetes-39 (D-39)] and distress [Problem Areas in Diabetes (PAID) Questionnaire], and cognitive function were assessed during and post-intervention. RESULTS: 61 (LC: 33, HC: 28) participants completed the study. Weight loss was 9.1% after 12 months and 6.7% after 2 years with no difference between diet groups. There were no differences between the groups for the changes in any psychological health outcome (smallest p ≥ 0.19 for all time x diet interactions). Overtime, improvements in BDI, POMS [Total Mood Disturbance (TMD); four subscales], PAID, and D-39 (three subscales) scores occurred (p ≤ 0.05, time). Stepwise regression analysis showed improvements in BDI, POMS (TMD; two subscales), D-39, SAI, and PAID scores were significantly (p < 0.05) correlated with reductions in body weight and glycated hemoglobin. CONCLUSION: In adults with obesity and T2DM, energy-restricted LC and HC diets produced comparable long-term improvements on a comprehensive range of psychological health outcomes. The findings suggest both diets can be used as a diabetes management strategy as part of a holistic lifestyle modification program without concern of negative effects on mental well-being or cognition. TRIAL REGISTRATION: ACTRN12612000369820, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=362168&isReview=true . Data described in the manuscript, code book, and analytic code will not be made available because approval has not been granted by participants.

Co-design of a digital dietary intervention for adults at risk of type 2 diabetes.

BACKGROUND: Co-design has the potential to create interventions that lead to sustainable health behaviour change. Evidence suggests application of co-design in various health domains has been growing; however, few public-facing digital interventions have been co-designed to specifically address the needs of adults at risk of Type 2 diabetes (T2D). This study aims to: (1) co-design, with key stakeholders, a digital dietary intervention to promote health behaviour change among adults at risk of T2D, and (2) evaluate the co-design process involved in developing the intervention prototype. METHODS: The co-design study was based on a partnership between nutrition researchers and designers experienced in co-design for health. Potential end-users (patients and health professionals) were recruited from an earlier stage of the study. Three online workshops were conducted to develop and review prototypes of an app for people at risk of T2D. Themes were inductively defined and aligned with persuasive design (PD) principles used to inform ideal app features and characteristics. RESULTS: Participants were predominantly female (range 58-100%), aged 38 to 63 years (median age = 59 years), consisting of a total of 20 end-users and four experts. Participants expressed the need for information from credible sources and to provide effective strategies to overcome social and environmental influences on eating behaviours. Preferred app features included tailoring to the individual's unique characteristics, ability to track and monitor dietary behaviour, and tools to facilitate controlled social connectivity. Relevant persuasive design principles included social support, reduction (reducing effort needed to reach target behaviour), tunnelling (guiding users through a process that leads to target behaviour), praise, rewards, and self-monitoring. The most preferred prototype was the Choices concept, which focusses on the users' journey of health behaviour change and recognises progress, successes, and failures in a supportive and encouraging manner. The workshops were rated successful, and feedback was positive. CONCLUSIONS: The study's co-design methods were successful in developing a functionally appealing and relevant digital health promotion intervention. Continuous engagement with stakeholders such as designers and end-users is needed to further develop a working prototype for testing.

Very Low and Higher Carbohydrate Diets Promote Differential Appetite Responses in Adults with Type 2 Diabetes: A Randomized Trial.

BACKGROUND: Effects of very low carbohydrate (VLC) diets on appetite response in individuals with type 2 diabetes remain unclear. OBJECTIVE: A secondary analysis was conducted to determine appetite responses to an energy-restricted [30% of energy (%E) deficit] very low carbohydrate (VLC) diet compared with a higher carbohydrate (HC) diet in adults who were overweight or obese with type 2 diabetes. METHODS: Forty-four men and 40 women (mean ± SD, age: 58.7 ± 6.6 y; weight: 100.4 ± 15.5 kg; BMI: 34.5 ± 4.1 kg/m2; glycated hemoglobin: 7.3 ± 1.0%; duration of diabetes: 6.7 ± 5.6 y) were randomly assigned to diets categorized as VLC [14%E carbohydrate (<50 g/d), 28%E protein, 58%E fat (<10%E saturated fat)], or energy-matched HC [53%E carbohydrate, 17%E protein, 30%E fat (<10%E saturated fat)] combined with progressive multicomponent exercise (60 min; 3 d/wk). Body weight, average weekly "daily fasting" and "daily overall" appetite perceptions (hunger, fullness, prospective consumption, and desire to eat-visual analog scales) were assessed at baseline and after 4 and 16 wk. Changes between diets over time were assessed using repeated measures ANOVA. RESULTS: Significant decreases in body weight did not differ between groups (VLC: -11.0 ± 5.4 kg/16 wk compared with HC: -10.1 ± 4.3 kg/16 wk, P = 0.40). Compared with HC, VLC had greater decreases in "daily overall" ratings of fullness (P time × diet < 0.01), such that scores were higher in HC at Week 4 (VLC:48 ± 3 vs HC:56 ± 3 mm, P = 0.001) and 16 (VLC:51 ± 2 vs HC:57 ± 3 mm, P = 0.019). Compared with HC, VLC had greater increases in prospective consumption ratings (P time × diet = 0.03), such that scores were lower in HC at Week 4 (VLC:33 ± 2 vs HC:28 ± 2 mm, P = 0.008), but not at Week 16 (VLC:33 ± 2 vs HC 31 ± 2 mm, P = 0.289). CONCLUSIONS: In the context of energy restriction, both HC and VLC energy-matched diets promoted comparable effects on fasting perceptions of appetite, but the HC diet resulted in greater "daily overall" fullness and reduced prospective consumption. Further research is required to evaluate the effects of ad libitum diets differing in amounts of carbohydrate on appetite response in populations with type 2 diabetes. This trial was registered at www.anzctr.org.au as ACTRN12612000369820.

Correction to: Comparison of the effects of weight loss from a high-protein versus standard-protein energy-restricted diet on strength and aerobic capacity in overweight and obese men.

The original version of this article unfortunately contained a mistake.

An evidence-based approach to developing low-carbohydrate diets for type 2 diabetes management: A systematic review of interventions and methods.

AIM: To identify core diet and delivery components of low-carbohydrate (CHO) diets that have demonstrated efficacy for type 2 diabetes (T2D) management. MATERIALS AND METHODS: MEDLINE, Pre-MEDLINE, EMBASE, CINAHL and the Cochrane Library of Controlled Trials databases were systematically searched from inception until August 18, 2018. Primary intervention studies of low-CHO diets (≤130 g/d or 26% total energy intake [TEI]) were included. Content analysis was performed on the low-CHO diet protocols classified as safe and effective for T2D management. RESULTS: A total of 41 studies published between 1963 and 2018 were included, of which 40 were classified as safe and effective for inclusion in the primary analysis. Thirteen studies (13/40) were on very-low-CHO diets (<50 g/d), 14/40 included low-CHO diets (≤130 g/d or 26% TEI), and 13/40 were adapted according to participant progress. Thirty-one studies reported a total energy prescription, of which 18/31 encouraged ad libitum intakes. Twenty studies reported a prescribed dietary fat amount, of which 18/20 were unrestricted or high-fat (>35% TEI). Twenty-six studies reported a prescribed dietary protein amount, of which 22 were unrestricted or were high-protein (>25% TEI). The types of dietary CHO, fat and protein recommended were predominantly whole foods. Common delivery methods reported were dietician and/or physician involvement, moderate to high frequency of contact (≥1 session/month) and use of participant self-monitoring. CONCLUSIONS: Multiple approaches for developing and delivering a low-CHO diet intervention for T2D management are safe and effective. A comprehensive set of core dietary components to consider in the formulation of low-CHO diet protocols were identified for use in clinical practice and to inform evidence-based guidelines for T2D management.

Effects of an energy-restricted low-carbohydrate, high unsaturated fat/low saturated fat diet versus a high-carbohydrate, low-fat diet in type 2 diabetes: A 2-year randomized clinical trial.

AIM: To examine whether a low-carbohydrate, high-unsaturated/low-saturated fat diet (LC) improves glycaemic control and cardiovascular disease (CVD) risk factors in overweight and obese patients with type 2 diabetes (T2D). METHODS: A total of 115 adults with T2D (mean [SD]; BMI, 34.6 [4.3] kg/m2 ; age, 58 [7] years; HbA1c, 7.3 [1.1]%) were randomized to 1 of 2 planned energy-matched, hypocaloric diets combined with aerobic/resistance exercise (1 hour, 3 days/week) for 2 years: LC: 14% energy as carbohydrate, 28% as protein, 58% as fat (<10% saturated fat); or low-fat, high-carbohydrate, low-glycaemic index diet (HC): 53% as CHO, 17% as protein, 30% as fat (<10% saturated fat). HbA1c, glycaemic variability (GV), anti-glycaemic medication effect score (MES, calculated based on the potency and dosage of diabetes medication), weight, body composition, CVD and renal risk markers were assessed before and after intervention. RESULTS: A total of 61 (LC = 33, HC = 28) participants completed the study (trial registration: http://www.anzctr.org.au/, ANZCTR No. ACTRN12612000369820). Reductions in weight (estimated marginal mean [95% CI]; LC, -6.8 [-8.8,-4.7], HC, -6.6 [-8.8, -4.5] kg), body fat (LC, -4.3 [-6.2, -2.4], HC, -4.6 [-6.6, -2.7] kg), blood pressure (LC, -2.0 [-5.9, 1.8]/ -1.2 [-3.6, 1.2], HC, -3.2 [-7.3, 0.9]/ -2.0 [-4.5, 0.5] mmHg), HbA1c (LC, -0.6 [-0.9, -0.3], HC, -0.9 [-1.2, -0.5] %) and fasting glucose (LC, 0.3 [-0.4, 1.0], HC, -0.4 [-1.1, 0.4] mmol/L) were similar between groups (P ≥ 0.09). Compared to HC, the LC achieved greater reductions in diabetes medication use (MES; LC, -0.5 [-0.6, -0.3], HC, -0.2 [-0.4, -0.02] units; P = 0.03), GV (Continuous Overall Net Glycemic Action calculated every 1 hour (LC, -0.4 [-0.6, -0.3], HC, -0.1 [-0.1, 0.2] mmol/L; P = 0.001), and 4 hours (LC, -0.9 [-1.3, -0.6], HC, -0.2 [-0.6, 0.1] mmol/L; P = 0.02)); triglycerides (LC, -0.1 [-0.3, 0.2], HC, 0.1 [-0.2, 0.3] mmol/L; P = 0.001), and maintained HDL-C levels (LC, 0.02 [-0.05, 0.1], HC, -0.1 [-0.1, 0.01] mmol/L; P = 0.004), but had similar changes in LDL-C (LC, 0.2 [-0.1, 0.5], HC, 0.1 [-0.2, 0.4] mmol/L; P = 0.85), brachial artery flow mediated dilatation (LC, -0.5 [-1.5, 0.5], HC, -0.4 [-1.4, 0.7] %; P = 0.73), eGFR and albuminuria. CONCLUSIONS: Both diets achieved comparable weight loss and HbA1c reductions. The LC sustained greater reductions in diabetes medication requirements, and in improvements in diurnal blood glucose stability and blood lipid profile, with no adverse renal effects, suggesting greater optimization of T2D management.

Glycemic Variability: Assessing Glycemia Differently and the Implications for Dietary Management of Diabetes.

The primary therapeutic target for diabetes management is the achievement of good glycemic control, of which glycated hemoglobin (HbA1c) remains the standard clinical marker. However, glycemic variability (GV; the amplitude, frequency, and duration of glycemic fluctuations around mean blood glucose) is an emerging target for blood glucose control. A growing body of evidence supports GV as an independent risk factor for diabetes complications. Several techniques have been developed to assess and quantify intraday and interday GV. Additionally, GV can be influenced by several nutritional factors, including carbohydrate quality, quantity; and distribution; protein intake; and fiber intake. These factors have important implications for clinical nutrition practice and for optimizing blood glucose control for diabetes management. This review discusses the available evidence for GV as a marker of glycemic control and risk factor for diabetes complications. GV quantification techniques and the influence of nutritional considerations for diabetes management are also discussed.

A randomised-controlled trial of the effects of very low-carbohydrate and high-carbohydrate diets on cognitive performance in patients with type 2 diabetes.

This study compared the longer-term effects of a very low-carbohydrate, high-fat diet with a high-carbohydrate, low-fat diet on cognitive performance in individuals with type 2 diabetes (T2D). In total, 115 obese adults with T2D (sixty-six males, BMI: 34·6 (sd 4·3) kg/m2, age: 58 (sd 7) years, HbA1c: 7·3 (sd 1·1) %, diabetes duration: 8 (sd 6) years) were randomised to consume either an energy-restricted, very low-carbohydrate, low-saturated-fat (LC) diet or an energy-matched high unrefined carbohydrate, low-fat (HC) diet with supervised aerobic/resistance exercise (60 min, 3 d/week) for 52 weeks. Body weight, HbA1c and cognitive performance assessing perceptual speed, reasoning speed, reasoning ability, working memory, verbal fluency, processing speed, short-term memory, inhibition and memory scanning speed were assessed before and after intervention. No differences in the changes in cognitive test performance scores between the diet groups were observed for any of the cognitive function outcomes assessed (P≥0·24 time×diet). Percentage reduction in body weight correlated with improvements with perceptual speed performance. In obese adults with T2D, both LC and HC weight-loss diets combined with exercise training had similar effects on cognitive performance. This suggests that an LC diet integrated within a lifestyle modification programme can be used as a strategy for weight and diabetes management without the concern of negatively affecting cognitive function.

Perceived exercise barriers are reduced and benefits are improved with lifestyle modification in overweight and obese women with polycystic ovary syndrome: a randomised controlled trial.

BACKGROUND: This study assessed the perceived benefits and barriers to exercise participation in overweight and obese women with polycystic ovary syndrome (PCOS) and monitored changes in response to a lifestyle intervention. METHODS: Forty-three overweight/obese PCOS women (Age, 30.3(6.2) yrs; BMI, 36.4(5.6) kg/m(2)) were randomised to one of three 20-week lifestyle programs: diet only (DO, n = 13), diet and aerobic exercise (DA, n = 11) and diet and combined aerobic-resistance exercise (DC, n = 19). Exercise Benefits/Barriers Scale (EBBS), weight, aerobic fitness, depression and PCOS specific health-related quality of life were measured. RESULTS: Barriers score was related to depression (r = 0.45, P = 0.002) and aerobic fitness (r = -0.32, P = 0.04), while benefits score was related to aerobic fitness (r = 0.41, P = 0.007). EBBS, benefits and barriers scores improved overtime (P ≤ 0.001). Benefits subscales psychological outlook and social interaction increased (P ≤ 0.001) and life enhancement and preventative health did not change (P ≥ 0.3). Physical performance increased only in DA (P = 0.009). There were no differences between treatments for any of the other subscales (P ≥ 0.2). Barriers subscales exercise milieu, time expenditure and physical exertion reduced (P ≤ 0.003) and family discouragement did not change (P = 0.6). CONCLUSIONS: This study demonstrated that lifestyle modification consisting of an energy-restricted diet with or without exercise training improved the perceived benefits from and barriers to exercise. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Register ACTRN12606000198527, registered 26 May 2006.

Long-term effects of a very low-carbohydrate weight loss diet on exercise capacity and tolerance in overweight and obese adults.

AIM: Compare the long-term effects of an energy-restricted very low-carbohydrate, high-fat (LC) diet with an isocaloric high-carbohydrate, low-fat (HC) diet on exercise tolerance and capacity in overweight and obese adults. METHODS: Seventy-six adults (25 males; age 49.2 ± 1.1 years; BMI 33.6 ± 0.5 kg/m(2)) were randomized to either a hypocaloric (6-7 MJ/day) LC diet (35% protein, 4% carbohydrate, 61% fat) or isocaloric HC diet (24% protein, 46% carbohydrate, 30% fat) for 52 weeks. Pre- and postintervention, participants' body weight and composition, handgrip, and isometric knee extensor strength were assessed and participants performed an incremental exercise test to exhaustion. RESULTS: Forty-three participants completed the study (LC = 23; HC = 20). Overall, peak relative oxygen uptake increased (+11.3%) and reductions occurred in body weight (-14.6%), body fat percentage (-6.9% [absolute]), isometric knee extensor strength (-12.4%), handgrip strength (-4.5%), and absolute peak oxygen uptake (-5.2%; p ≤ 0.02 time for all) with no diet effect (p ≥ 0.18). During submaximal exercise, rating of perceived exertion did not change in either group (p = 0.16 time, p = 0.59 Time × Group). Compared to the HC diet, the LC diet had greater reductions in respiratory exchange ratio (LC -0.04 ± 0.01, HC -0.00 ± 0.01; p = 0.03), and increased fat oxidation (LC 15.0 ± 5.3% [of energy expenditure], HC 0.5 ± 3.9%; p = 0.04). CONCLUSION: In overweight and obese patients, an LC diet promoted greater fat utilization during submaximal exercise. Both an LC diet and an HC diet had similar effects on aerobic capacity and muscle strength, suggesting that long-term consumption of an LC weight loss diet does not adversely affect physical function or the ability to perform exercise.

Comparison of the effects of weight loss from a high-protein versus standard-protein energy-restricted diet on strength and aerobic capacity in overweight and obese men.

PURPOSE: To compare the effects of two low-fat, hypoenergetic diets differing in carbohydrate-to-protein ratio, on strength and aerobic capacity measures in overweight and obese men. METHODS: In a parallel design, 56 men (age, 45.5 ± 8.7 years; BMI, 33.6 ± 3.9 kg/m(2)) were randomly assigned to a low-fat, energy-restricted diet (7,000 kJ/day) with either high protein (HP: protein/carbohydrate/fat % energy, 35:40:25) or standard protein (SP, 17:58:25). Body weight, body composition, muscle strength and aerobic capacity were assessed at baseline and after 12 weeks. RESULTS: Forty-two participants completed the study (HP, n = 21; SP, n = 21). Both groups experienced similar reductions in body weight (HP, -10.7 ± 5.3 kg [-9.8%]; SP, -8.7 ± 3.5 kg [-8.4%]) and fat-free mass (HP, -2.8 ± 3.6 kg; SP, -3.2 ± 2.7 kg; P < 0.001 time; P > 0.14 time × group interaction). There was a trend for a greater reduction in fat mass in the HP diet group, (-7.7 ± 4.3 kg [-21.2%] vs. -5.4 ± 3.3 kg [-15.1%]; P < 0.001 time; P = 0.06 time × group interaction). Absolute peak oxygen uptake did not change in either group (P = 0.39 time; P = 0.50 time × group interaction). Overall, in both groups, relative peak oxygen uptake increased (2.9 ± 2.8 ml kg(-1) min(-1) [8.9%]), peak isometric knee extensor strength increased (14.1 ± 35.7 Nm [7.1%]) and peak handgrip strength decreased (-1.6 ± 4.1 kg [-3%]) (P ≤ 0.02 time for all), with no diet effect (P ≤ 0.23 time × group interaction). CONCLUSION: In overweight and obese men, both a HP and SP diet reduced body weight and improved body composition with similar effects on strength and aerobic capacity.

A primary care delivered, technology supported lifestyle program for Type 2 Diabetes Management: An evaluation of changes in metabolic health, feasibility, and acceptability - A pilot interventional study protocol.

Background: Type 2 Diabetes (T2D) is associated with significant health complications and socioeconomic costs. Previous research conducted through an outpatient research facility demonstrated use of a low carbohydrate (LC) diet and exercise plan delivered in the format of an education book combined with use of real-time continuous glucose monitoring (RT-CGM) is an effective self-management intervention to improve weight and blood glucose management in patients with T2D. Primary health care remains the central access point for patient management of T2D, but General Practitioners (GPs) lack access to effective evidenced-based, self-management programs that can be prescribed to improve patient outcomes. Methods: A single-arm, within-participant pilot intervention study will be conducted to evaluate the changes in metabolic health, acceptability and feasibility of a prescriptive LC diet and lifestyle program combined with RT-CGM (LC-RTC) delivered via GP practices. Forty adults with T2D will be recruited from GP practices and prescribed the LC-RTC intervention for 12 weeks. Outcomes will be assessed at baseline and 12-weeks post intervention. Changes in metabolic health will be assessed by changes in glycosylated hemoglobin (primary outcome), body weight, blood pressure, blood lipids, and medication usage. Post-intervention, participants will complete questionnaires and participate in focus groups to explore their experience of the LC-RTC program including acceptance, perceived benefits/barriers, limitations, financial feasibility, intervention drop-out rates, participant and GP engagement with the program (clinic attendance and contacts made to clinic for program support) and RT-CGM use and wear time acceptance. GPs and clinical staff involved will participate focus groups to evaluate the perceived value and feasibility of the LC-RTC program. Discussion: This trial will provide a powered evaluation of the changes in metabolic health, acceptability, and feasibility of the LC-RTC program for patients with T2D delivered via GP practices. Trial registration: ANZCTR: 12622000635763 (Website Link to full registration: ANZCTR - Registration). Registered 29th April 2022. Overall trial status: Commenced; Recruitment Status: Commenced 1st May 2022, with 40 participants recruited as of 2nd May 2023 using a rolling recruitment approach.

Effects of a low-carbohydrate diet in adults with type 1 diabetes management: A single arm non-randomised clinical trial.

Public interest in low-carbohydrate (LC) diets for type 1 diabetes (T1D) management has increased. This study compared the effects of a healthcare professional delivered LC diet compared to habitual diets higher in carbohydrates on clinical outcomes in adults with T1D. Twenty adults (18-70 yrs) with T1D (≥6 months duration) with suboptimal glycaemic control (HbA1c>7.0% or >53 mmol/mol) participated in a 16-week single arm within-participant, controlled intervention study involving a 4-week control period following their habitual diets (>150 g/day of carbohydrates) and a 12-week intervention period following a LC diet (25-75 g/day of carbohydrates) delivered remotely by a registered dietitian. Glycated haemoglobin (HbA1c -primary outcome), time in range (blood glucose: 3.5-10.0 mmol/L), frequency of hypoglycaemia (<3.5 mmol/L), total daily insulin, and quality of life were assessed before and after the control and intervention periods. Sixteen participants completed the study. During the intervention period, there were reductions in total dietary carbohydrate intake (214 to 63 g/day; P<0.001), HbA1c (7.7 to 7.1% or 61 to 54 mmol/mol; P = 0.003) and total daily insulin use (65 to 49 U/day; P<0.001), increased time spent in range (59 to 74%; P<0.001), and improved quality of life (P = 0.015), with no significant changes observed during the control period. Frequency of hypoglycaemia episodes did not differ across timepoints, and no episodes of ketoacidosis or other adverse events were reported during the intervention period. These preliminary findings suggest that a professionally supported LC diet may lead to improvements in markers of blood glucose control and quality of life with reduced exogenous insulin requirements and no evidence of increased hypoglycaemia or ketoacidosis risk in adults with T1D. Given the potential benefits of this intervention, larger, longer-term randomised controlled trials are warranted to confirm these findings. Trial Registration: https://www.anzctr.org.au/ACTRN12621000764831.aspx.

A Health Care Professional Delivered Low Carbohydrate Diet Program Reduces Body Weight, Haemoglobin A1c, Diabetes Medication Use and Cardiovascular Risk Markers-A Single-Arm Intervention Analysis.

This study examined the effectiveness of a health care professional delivered low-carbohydrate diet program (Diversa Health Program) aiming to improve obesity/type-2-diabetes management for people living in Australia. 511 adults (Age:57.1 ± 13.7 [SD] yrs) who participated between January 2017−August 2021 for ≥30 days with pre-post data collected for ≥1 key outcome variable (body weight and HbA1c) were included in the analysis. Average participation duration was 218 ± 207 days with 5.4 ± 3.9 reported consultation visits. Body weight reduced from 92.3 ± 23.0 to 86.3 ± 21.1 kg (n = 506, p < 0.001). Weight loss was 0.9 ± 2.8 kg (1.3%), 4.5 ± 4.3 kg (5.7%) and 7.9 ± 7.2 kg (7.5%), respectively, for those with a classification of normal weight (n = 67), overweight (n = 122) and obese (n = 307) at commencement. HbA1c reduced from 6.0 ± 1.2 to 5.6 ± 0.7% (n = 212, p < 0.001). For members with a commencing HbA1c of <5.7% (n = 110), 5.7−6.4% (n = 55), and ≥6.5% (n = 48), HbA1c reduced −0.1 ± 0.2%, −0.3 ± 0.3%, and −1.4 ± 1.3%, respectively. For members with a commencing HbA1c ≥6.5%, 90% experienced a HbA1c reduction and 54% achieved a final HbA1c < 6.5%. With inclusion and exclusion of metformin, respectively, 124 and 82 diabetes medications were prescribed to 63 and 42 members that reduced to 82 and 35 medications prescribed to 51 and 26 members at final visit. A health care professional delivered low-carbohydrate diet program can facilitate weight loss and improve glycaemic control with greatest improvements and clinical relevance in individuals with worse baseline parameters.

The Carbohydrate Threshold in Pregnancy and Gestational Diabetes: How Low Can We Go?

The original nutrition approach for the treatment of gestational diabetes mellitus (GDM) was to reduce total carbohydrate intake to 33-40% of total energy (EI) to decrease fetal overgrowth. Conversely, accumulating evidence suggests that higher carbohydrate intakes (60-70% EI, higher quality carbohydrates with low glycemic index/low added sugars) can control maternal glycemia. The Institute of Medicine (IOM) recommends ≥175 g/d of carbohydrate intake during pregnancy; however, many women are consuming lower carbohydrate (LC) diets (<175 g/d of carbohydrate or <40% of EI) within pregnancy and the periconceptual period aiming to improve glycemic control and pregnancy outcomes. This report systematically evaluates recent data (2018-2020) to identify the LC threshold in pregnancy in relation to safety considerations. Evidence from 11 reports suggests an optimal carbohydrate range of 47-70% EI supports normal fetal growth; higher than the conventionally recognized LC threshold. However, inadequate total maternal EI, which independently slows fetal growth was a frequent confounder across studies. Effects of a carbohydrate intake <175 g/d on maternal ketonemia and plasma triglyceride/free fatty acid concentrations remain unclear. A recent randomized controlled trial (RCT) suggests a higher risk for micronutrient deficiency with carbohydrate intake ≤165 g/d in GDM. Well-controlled prospective RCTs comparing LC (<165 g/d) and higher carbohydrate energy-balanced diets in pregnant women are clearly overdue.

Co-Design Practices in Diet and Nutrition Research: An Integrative Review.

Co-design, the method of involving users, stakeholders, and practitioners in the process of design, may assist to improve the translation of health evidence into tangible and acceptable intervention prototypes. The primary objective of this review was to identify and describe co-design techniques used in nutrition research. The secondary objective was to identify associations between co-design techniques and intervention effectiveness. An integrative review was performed using the databases Emcare, MEDLINE, PsycINFO and Google Scholar. Eligible studies included those that: (1) utilised participatory research or co-design techniques, (2) described development and/or evaluation of interventions aimed at improving dietary behaviours or nutrition, and (3) targeted community-dwelling adults aged ≥18 years. We identified 2587 studies in the initial search and included 22 eligible studies. There were 15 studies that utilised co-design techniques, with a strong focus on engagement of multiple stakeholder types and use of participatory research techniques. No study implemented a complete co-design process. Most studies (14/15) reporting outcomes reported positive health (maximum p < 0.001) or health behaviour outcomes attributed to the intervention; hence, associations between co-design techniques and effectiveness could not be determined. Currently published intervention studies have used participatory research approaches rather than co-design methods. Future research is required to explore the effectiveness of co-design nutrition interventions.

Identifying critical features of type two diabetes prevention interventions: A Delphi study with key stakeholders.

AIMS: This study aims to identify critically important features of digital type two diabetes mellitus (T2DM) prevention interventions. METHODS: A stakeholder mapping exercise was undertaken to identify key end-user and professional stakeholders, followed by a three-round Delphi procedure to generate and evaluate evidence statements related to the critical elements of digital T2DM prevention interventions in terms of product (intervention), price (funding models/financial cost), place (distribution/delivery channels), and promotion (target audiences). RESULTS: End-user (n = 38) and professional (n = 38) stakeholders including patients, dietitians, credentialed diabetes educators, nurses, medical doctors, research scientists, and exercise physiologists participated in the Delphi study. Fifty-two critical intervention characteristics were identified. Future interventions should address diet, physical activity, mental health (e.g. stress, diabetes-related distress), and functional health literacy, while advancing behaviour change support. Programs should be delivered digitally or used multiple delivery modes, target a range of population subgroups including children, and be based on collaborative efforts between national and local and government and non-government funded organisations. CONCLUSIONS: Our findings highlight strong support for digital health to address T2DM in Australia and identify future directions for T2DM prevention interventions. The study also demonstrates the feasibility and value of stakeholder-led intervention development processes.

Almond consumption affects fecal microbiota composition, stool pH, and stool moisture in overweight and obese adults with elevated fasting blood glucose: A randomized controlled trial.

Regular almond consumption has been shown to improve body weight management, lipid profile and blood glucose control. We hypothesized that almond consumption would alter fecal microbiota composition, including increased abundance and activity of potentially beneficial bacterial taxa in adults who are overweight and obese with elevated fasting blood glucose. A total of 69 adults who were overweight or obese with an elevated plasma glucose (age: 60.8 ± 7.4, BMI ≥27 kg/m2, fasting plasma glucose ≥5.6 to <7.0 mmol/L) were randomized to daily consumption of either 2 servings of almonds (AS:56 g/day) or an isocaloric, high carbohydrate biscuit snack for 8 weeks. AS but not biscuit snack experienced significant changes in microbiota composition (P= .011) and increases in bacterial richness, evenness, and diversity (P< .01). Increases in both the relative and absolute abundance of operational taxonomic units in the Ruminococcaceae family, including Ruminiclostridium (false discovery rate P = .002), Ruminococcaceae NK4A214 (P = .002) and Ruminococcaceae UCG-003 (P = .002) were the principal drivers of microbiota-level changes. No changes in fecal short chain fatty acid levels, or in the carriage of the gene encoding butyryl-CoA:acetate CoA-transferase (an enzyme involved in butyrate synthesis) occurred. Almond consumption was not associated with reduced gut permeability, but fecal pH (P= .0006) and moisture content (P = .027) decreased significantly in AS when compared to BS. Regular almond consumption increased the abundance of potentially beneficial ruminococci in the fecal microbiota in individuals with elevated blood glucose. However, fecal short-chain fatty acid levels remained unaltered and the capacity for such microbiological effects to precipitate host benefit is not known.

Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data.

OBJECTIVE: To determine the efficacy and safety of low carbohydrate diets (LCDs) and very low carbohydrate diets (VLCDs) for people with type 2 diabetes. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Searches of CENTRAL, Medline, Embase, CINAHL, CAB, and grey literature sources from inception to 25 August 2020. STUDY SELECTION: Randomized clinical trials evaluating LCDs (<130 g/day or <26% of a 2000 kcal/day diet) and VLCDs (<10% calories from carbohydrates) for at least 12 weeks in adults with type 2 diabetes were eligible. DATA EXTRACTION: Primary outcomes were remission of diabetes (HbA1c <6.5% or fasting glucose <7.0 mmol/L, with or without the use of diabetes medication), weight loss, HbA1c, fasting glucose, and adverse events. Secondary outcomes included health related quality of life and biochemical laboratory data. All articles and outcomes were independently screened, extracted, and assessed for risk of bias and GRADE certainty of evidence at six and 12 month follow-up. Risk estimates and 95% confidence intervals were calculated using random effects meta-analysis. Outcomes were assessed according to a priori determined minimal important differences to determine clinical importance, and heterogeneity was investigated on the basis of risk of bias and seven a priori subgroups. Any subgroup effects with a statistically significant test of interaction were subjected to a five point credibility checklist. RESULTS: Searches identified 14 759 citations yielding 23 trials (1357 participants), and 40.6% of outcomes were judged to be at low risk of bias. At six months, compared with control diets, LCDs achieved higher rates of diabetes remission (defined as HbA1c <6.5%) (76/133 (57%) v 41/131 (31%); risk difference 0.32, 95% confidence interval 0.17 to 0.47; 8 studies, n=264, I2=58%). Conversely, smaller, non-significant effect sizes occurred when a remission definition of HbA1c <6.5% without medication was used. Subgroup assessments determined as meeting credibility criteria indicated that remission with LCDs markedly decreased in studies that included patients using insulin. At 12 months, data on remission were sparse, ranging from a small effect to a trivial increased risk of diabetes. Large clinically important improvements were seen in weight loss, triglycerides, and insulin sensitivity at six months, which diminished at 12 months. On the basis of subgroup assessments deemed credible, VLCDs were less effective than less restrictive LCDs for weight loss at six months. However, this effect was explained by diet adherence. That is, among highly adherent patients on VLCDs, a clinically important reduction in weight was seen compared with studies with less adherent patients on VLCDs. Participants experienced no significant difference in quality of life at six months but did experience clinically important, but not statistically significant, worsening of quality of life and low density lipoprotein cholesterol at 12 months. Otherwise, no significant or clinically important between group differences were found in terms of adverse events or blood lipids at six and 12 months. CONCLUSIONS: On the basis of moderate to low certainty evidence, patients adhering to an LCD for six months may experience remission of diabetes without adverse consequences. Limitations include continued debate around what constitutes remission of diabetes, as well as the efficacy, safety, and dietary satisfaction of longer term LCDs. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020161795.

Adults with and without type 1 diabetes have similar energy and macronutrient intakes: an analysis from the Australian Health Survey 2011-2013.

The aim of this study was to describe and compare the mean usual dietary intakes of adults with type 1 diabetes (T1D) and without diabetes living in Australia. Our hypothesis was that adults with T1D have similar dietary intake profiles to adults without diabetes. Data from the National Nutrition and Physical Activity Survey 2011-2012, which formed part of the Australian Health Survey 2011-13, were used and participants ≥18 years of age with T1D and without diabetes were included in the analyses. T1D status was assigned to participants who reported a diabetes diagnosis at age <25 years and still had diabetes at the time of survey completion. Mean usual intakes of energy, macronutrients and carbohydrate-rich food groups, measured by 24-hour recall, were compared between groups using Analysis of Covariance after adjustment for age, sex, socioeconomic status, smoking status and body mass index. The number of adults classified with T1D and without diabetes was n = 43 and n = 8844, respectively. The T1D group had a mean energy intake (%E) of 7873 kJ/day with 45%E from carbohydrates (213 g/day), 31%E from fats (67 g/day) and 20%E from proteins (88 g/day). There were no significant differences in energy or macronutrient intakes between groups (P ≥ .07), except individuals with T1D reported higher intakes of whole grains and high fiber cereals, after multivariable adjustment (2.4 vs 1.7 serves/day; P = .02). In conclusion, adults with and without T1D had similar reported energy and macronutrient intake profiles that are consistent with current dietary recommendations for T1D management and healthy eating guidelines for the general population.