The effects of meal glycemic load on blood glucose levels of adults with different body mass indexes

The Impact of Ketogenic Nutrition on Obesity and Metabolic Health: Mechanisms and Clinical Implications

The ketogenic diet (KD) has recently gained increasing popularity. This high-fat, adequate-protein, and carbohydrate-poor eating pattern leads to nutritional ketosis. The KD has long been known for its antidiabetic and antiepileptic effects and has been used therapeutically in these contexts. Recently, the KD, due to its effectiveness in inducing weight loss, has also been proposed as a possible approach to treat obesity. Likewise, a KD is currently explored as a supporting element in the treatment of obesity-associated metabolic disorders and certain forms of cancer. Here, we discuss the metabolic and biochemical mechanisms at play during the shift of metabolism to fatty acids and fatty acid-derived ketone bodies as main fuel molecules, in the substitution of carbohydrates, in ketogenic nutrition. Different sources of ketone bodies and KDs as alternatives to glucose and carbohydrates as main energy substrates are discussed, together with an attempt to weigh the benefits and risks posed by the chronic use of a KD in the context of weight loss, and also considering the molecular effects that ketone bodies exert on metabolism and on the endocrine system.

Behavior and physiology in female Cricetulus barabensis are associated with the expression of circadian genes

The circadian clock regulates the behavior, physiology, and metabolism of mammals, and these characteristics, such as sleep-wake cycles, exercise capacity, and hormone levels, exhibit circadian rhythms. Light signaling is the main stimulator of the mammalian circadian system. The photoperiod regulates the reproductive cycle of seasonal breeding animals, and the circadian clock plays a pivotal role in this process. However, the role of the clock in coordinating animal behavior and physiology in response to photoperiodic changes needs further investigation. The present study investigated the changes and correlation of behavioral activities, physiological indicators, and gene expression in female striped hamsters (Cricetulus barabensis) within 24 h under a 12L:12D photoperiod. We found that the daily rhythms of sleep-wake and open field were significant in hamsters. The expression of clock genes, melatonin receptor genes, and genes involved in general metabolism oscillated significantly in central and peripheral tissues (brain, hypothalamus, liver, ovary, and thymus) and was significantly associated with behavior and physiology. Our results revealed that the neuroendocrine system regulated the rhythmicity of behavior and physiology, and central and peripheral clock genes (Bmal1, Clock, Per1, Per2, Cry1, and Cry2), melatonin receptor genes (MT1, MT2, and GPR50), and metabolizing genes (SIRT1, FGF21, and PPARα) played important roles. Our results suggest that central and peripheral circadian clocks, melatonin receptors, and genes involved in general metabolism may play key roles in maintaining circadian behavior and metabolic homeostasis in striped hamsters. Our results may have important implication for rodent pest control.

Evaluation of a Continuous Blood Glucose Monitor: A Novel and Non-Invasive Wearable Using Bioimpedance Technology

BACKGROUND

Frequent blood glucose level (BGL) monitoring is essential for effective diabetes management. Poor compliance is common due to the painful finger pricking or subcutaneous lancet implantation required from existing technologies. There are currently no commercially available non-invasive devices that can effectively measure BGL. In this real-world study, a prototype non-invasive continuous glucose monitoring system (NI-CGM) developed as a wearable ring was used to collect bioimpedance data. The aim was to develop a mathematical model that could use these bioimpedance data to estimate BGL in real time.

METHODS

The prototype NI-CGM was worn by 14 adult participants with type 2 diabetes for 14 days in an observational clinical study. Bioimpedance data were collected alongside paired BGL measurements taken with a Food and Drug Administration (FDA)-approved self-monitoring blood glucose (SMBG) meter and an FDA-approved CGM. The SMBG meter data were used to improve CGM accuracy, and CGM data to develop the mathematical model.

RESULTS

A gradient boosted model was developed using a randomized 80-20 training-test split of data. The estimated BGL from the model had a Mean Absolute Relative Difference (MARD) of 17.9%, with the Parkes error grid (PEG) analysis showing 99% of values in clinically acceptable zones A and B.

CONCLUSIONS

This study demonstrated the reliability of the prototype NI-CGM at collecting bioimpedance data in a real-world scenario. These data were used to train a model that could successfully estimate BGL with a promising MARD and clinically relevant PEG result. These results will enable continued development of the prototype NI-CGM as a wearable ring.

Common Bean Seeds Obtained by Plant Water Restriction Ameliorates Obesity-Associated Cardiovascular Risk and Insulin Resistance

The inclusion of beans in the diet has been recommended for obesity control. However, its beneficial effect varies depending on agroclimatic factors acting during plant development. The antiobesogenic capacity of Dalia bean (DB) seeds obtained by water restriction (WR) during the vegetative or reproductive stage of plant growth (50/100 and 100/50% of soil moisture in vegetative/reproductive stage, respectively), during the whole cycle (50/50), and well-watered plants (100/100) was researched. After phytochemical characterization, harvested beans from each experimental unit were pooled among treatments, based on a multivariate canonical discriminant analysis considering concentration of non-digestible carbohydrates (total, soluble and insoluble dietary fiber and resistant starch), phenolic compounds (total phenols, flavonoids, anthocyanins and condensed tannins) and total saponins, which showed no differences among replicas of each treatment. Obesity was induced in rats (UAZ-2015-36851) with a high fat diet (HFD) for four months. Afterwards, rats were fed with the HFD supplemented with 20% of cooked DB for three months. During treatment, 100/50 beans, improved blood triglycerides, cholesterol, and glucose, and alleviated early insulin resistance (IR) related to inhibition of lipase, α-amylase and -glucosidase activity. After sacrifice, a hypolipidemic capacity and atherogenic risk reduction was observed, especially from the 100/50 treatment, suggesting that intake of DB obtained from WR may prevent IR and dyslipidemia.

The solution properties of galactomannan after simulated digestion of guar fortified bread predict the extent of postprandial insulin reduction in healthy adult overweight subjects

Coil overlap occurs when random coil polysaccharides such as cereal beta-glucan or galactomannan in solution are abundant enough and large enough to entangle with one another to form networks. It was recently shown that this concept applied to in vitro digested cereal-based foods could predict the efficacy of the food to reduce postprandial glycaemia. In the current study we further investigate the role of coil overlap for prediction of glycaemic and insulinaemic responses using four guar fortified breads (10-15% wheat flour replacement level) with galactomannans of different weight-average molecular weight (M_w). The breads, including a wheat flour control, were tested in a randomised crossover study in 12 overweight adults. Addition of guar reduced postprandial serum insulin, but not glucose responses. The extent of postprandial insulin reduction correlated with the solution properties of galactomannan after in vitro digestion. A significantly greater reduction in insulin response was observed for two of the breads where the galactomannan M_w and concentration in solution after in vitro digestion was above coil overlap, in contrast to two other breads, which resulted in digests containing galactomannan below coil overlap and a significantly lower reduction of postprandial insulin. Further in vitro digestion experiments focusing on amylolysis of starch with kinetic modelling showed a greater proportion of slowly digested starch in breads with galactomannan above coil overlap than below. A combination of the molecular weight of dietary fibre in a food and its soluble concentration are key parameters explaining its physiological efficiency in the upper gastrointestinal tract.

The impact of glycaemic load on cognitive performance: A meta-analysis and guiding principles for future research

The effect of breakfast glycaemic load (GL) on cognition was systematically examined. Randomised and non-randomised controlled trials were identified using PubMed, Scopus, and Cochrane Library (up to May 2022). 15 studies involving adults (aged 20 - 80 years) were included. Studies had a low risk, or some concerns, of bias. A random-effects meta-analysis model revealed no effect of GL on cognition up to 119 min post-consumption. However, after 120 min, immediate episodic memory scores were better following a low-GL compared to a high-GL (SMD = 0.16, 95% confidence interval [CI] = -0.00 to 0.32, p = 0.05, I2 = 5%). Subgroup analyses indicated that the benefit was greater in younger adults (<35 years) and those with better GT. A qualitative synthesis of 16 studies involving children and adolescents (aged 5 - 17 years) suggested that a low-GL breakfast may also benefit episodic memory and attention after 120 min. Methodological practises were identified which could explain a failure to detect benefits in some studies. Consequently, guiding principles were developed to optimise future study design.

African Cuisine-Centered Insulin Therapy: Expert Opinion on the Management of Hyperglycaemia in Adult Patients with Type 2 Diabetes Mellitus

The prevalence of diabetes in sub-Saharan Africa (SSA) is growing rapidly, and a steadily increasing number of adults are estimated to be living with type 2 diabetes mellitus (T2DM). Insulin therapy is the treatment of choice in patients who present with severe hyperglycaemia and in most of those who do not achieve target goals on oral hypoglycaemic agents. Initiating treatment with the appropriate type of insulin based on the meal patterns and lifestyle of the individual patient is a strategy that is more likely than others to improve glycaemic control and adherence. African cuisine typically has a high carbohydrate load. Given these predominantly carbohydrate-rich food habits, it is essential to modify this dietary pattern whilst at the same time ensuring that insulin therapy is initiated, titrated and maintained in a timely manner, as needed to suit the patient's habits. To date, there are no published clinical guidelines to guide practitioners and patients on tailoring insulin to match the high carbohydrate content in African cuisine. To address this gap, we have reviewed current insulin therapy practices and propose a patient-centric guide to insulin therapy based on African cuisine. A literature search was conducted for studies published in English up to November 2019 that focused on the choice of insulin and its dosing in relation to African foods. All articles extracted were reviewed by an expert group. The recommendation of the expert group was that basal-bolus and premix insulin regimens are best suited to manage post-meal glycaemia in African cuisine. The timing and constituents of the meal, portion sizes, glycaemic load and glycaemic index of meals should be considered when choosing the type of insulin and insulin regimen. Assessment of individual preferences and comorbidities should be prioritised and form an integral part of diabetes management.

A single one-minute, comfortable paced, stair-climbing bout reduces postprandial glucose following a mixed meal

BACKGROUND AND AIMS

Postprandial blood glucose (PBG) is an independent predictor of disease and mortality risk. To date, the shortest, single, moderate-intensity exercise intervention to reduce PBG is a 1 min bout of stair stepping during an oral glucose tolerance test. Whether this effect translates to real meal consumption is unknown.

METHODS AND RESULTS

Subjects (N = 30) participated in a randomized controlled crossover trial performing 0 min (seated control), 1 min, 3 min or 10 min of stair climbing and descending bouts (SCD) at a self-selected pace after consumption of a mixed meal on four separate visits. Compared to control, all SCD reduced PBG at least one timepoint: at 30-min the 3 min (-10.8 (-18.7 to -2.8) mg/dL, p = 0.010) and 10 min (-36.3 (-46.4 to -26.3) mg/dL), p < .001), and at 45-min the 1 min (-7.3 (-13.9 to -0.7) mg/dL, p = 0.030, 3 min (-8.7 (-13.9 to -3.6) mg/dL, p = 0.002 and 10 min SCD (-12.2 (-18.2 to -6.1)mg/dL, p < 0.000) reduced PBG. The area under the curve (AUC) for PBG was lower following the 3 min (-4.4% (-7.5 to -1.4%), p = 0.006) and 10 min (-8.9% (-12.4 to -5.3%), p < 0.001), while the incremental AUC (iAUC) was reduced only following the 10 min (-38.0% (-63.7 to -12.3%), p = 0.005) SCD. All SCD were rated by subjects as very light to light intensity.

CONCLUSIONS

Single, subjectively "light" intensity stair climbing and descending bouts as short as 1 min in duration attenuate the postprandial glucose response in normal weight individuals following consumption of a mixed meal. More pronounced effects require longer bouts in a dose-dependent manner.

Diet-induced differences in estimated plasma glucose concentrations in healthy, non-diabetic adults are detected by continuous glucose monitoring-a randomized crossover trial

Continuous glucose monitors (CGMs) have been developed for diabetic patients for estimating and controlling plasma glucose changes throughout the day. However, elevated postprandial glucose concentrations may also be detrimental for non-diabetic subjects by increasing the risk of developing vascular complications and type 2 diabetes. Therefore, CGMs may also be valuable in clinical research and we hypothesized that diet-induced differences in estimated plasma glucose concentrations in healthy, non-diabetic adults could be detected by the Abbott FreeStyle Libre Pro CGM. In this single-blind randomized cross-over trial, 23 healthy but overweight or obese men and women therefore consumed two diets differing in glycemic load in randomized order for three consecutive days. Based on the CGM measurements, two-hour total areas under the curve (tAUCs) after breakfast, lunch and dinner were calculated. Additionally, postprandial glucose was measured with the CGM and in plasma during a rice meal challenge. The average tAUC was significantly lower on the low GL diet compared to the high GL diet (P < .0001). The same conclusions were drawn when tAUCs for breakfast (P < .0001), lunch (P < .0001) and dinner (P < .0001) were analyzed separately. During the rice meal challenge, significantly higher glucose responses were observed after the low GL period, as monitored by both the CGM device (P < .0001) and the plasma glucose analysis (P < .0001). The difference between the means of both methods was 0.11 mmol/L (1.78%) with a higher glucose value in plasma. The absolute mean difference was 0.66 mmol/L (10.5%). We conclude that the CGM detected diet-induced differences in estimated plasma glucose concentrations, which supports its use not only in clinical practice, but also for research purposes during dietary interventions in non-diabetic participants.