A review of decision aids to assess cardiovascular risk.

PURPOSE OF REVIEW: Cardiovascular disease remains one of the leading causes of morbidity and mortality today. The major risk factors for cardiovascular disease include type 2 diabetes mellitus, hypertension, tobacco smoking, elevated body mass index, and hyperlipidemia. The decision to use medication treatment for hyperlipidemia can be assisted using computerized decision tools. RECENT FINDINGS: The treatment of hyperlipidemia with 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors has become widely recommended even though most people treated with them do not get clinical benefit, and the magnitude of their effect is dependent upon prior clinical risk. This article reviews recent research about the effectiveness of HMG-CoA reductase inhibitors, and the use of decision-making tools to assist the clinician in advising patients about the use of these medications. SUMMARY: On-line decision tools are available to estimate cardiovascular risk and to assist clinicians in helping their patients make their own decision about whether to take HMG-CoA reductase inhibitor medication to reduce cardiovascular risk.

Competing paradigms of obesity pathogenesis: energy balance versus carbohydrate-insulin models.

The obesity pandemic continues unabated despite a persistent public health campaign to decrease energy intake ("eat less") and increase energy expenditure ("move more"). One explanation for this failure is that the current approach, based on the notion of energy balance, has not been adequately embraced by the public. Another possibility is that this approach rests on an erroneous paradigm. A new formulation of the energy balance model (EBM), like prior versions, considers overeating (energy intake > expenditure) the primary cause of obesity, incorporating an emphasis on "complex endocrine, metabolic, and nervous system signals" that control food intake below conscious level. This model attributes rising obesity prevalence to inexpensive, convenient, energy-dense, "ultra-processed" foods high in fat and sugar. An alternative view, the carbohydrate-insulin model (CIM), proposes that hormonal responses to highly processed carbohydrates shift energy partitioning toward deposition in adipose tissue, leaving fewer calories available for the body's metabolic needs. Thus, increasing adiposity causes overeating to compensate for the sequestered calories. Here, we highlight robust contrasts in how the EBM and CIM view obesity pathophysiology and consider deficiencies in the EBM that impede paradigm testing and refinement. Rectifying these deficiencies should assume priority, as a constructive paradigm clash is needed to resolve long-standing scientific controversies and inform the design of new models to guide prevention and treatment. Nevertheless, public health action need not await resolution of this debate, as both models target processed carbohydrates as major drivers of obesity.

The Ketogenic Diet for Refractory Mental Illness: A Retrospective Analysis of 31 Inpatients.

Background and Hypothesis: The robust evidence base supporting the therapeutic benefit of ketogenic diets in epilepsy and other neurological conditions suggests this same metabolic approach may also benefit psychiatric conditions. Study Design: In this retrospective analysis of clinical care, 31 adults with severe, persistent mental illness (major depressive disorder, bipolar disorder, and schizoaffective disorder) whose symptoms were poorly controlled despite intensive psychiatric management were admitted to a psychiatric hospital and placed on a ketogenic diet restricted to a maximum of 20 grams of carbohydrate per day as an adjunct to conventional inpatient care. The duration of the intervention ranged from 6 to 248 days. Study Results: Three patients were unable to adhere to the diet for >14 days and were excluded from the final analysis. Among included participants, means and standard deviations (SDs) improved for the Hamilton Depression Rating Scale scores from 25.4 (6.3) to 7.7 (4.2), P < 0.001 and the Montgomery-Åsberg Depression Rating Scale from 29.6 (7.8) to 10.1 (6.5), P < 0.001. Among the 10 patients with schizoaffective illness, mean (SD) of the Positive and Negative Syndrome Scale (PANSS) scores improved from 91.4 (15.3) to 49.3 (6.9), P < 0.001. Significant improvements were also observed in metabolic health measures including weight, blood pressure, blood glucose, and triglycerides. Conclusions: The administration of a ketogenic diet in this semi-controlled setting to patients with treatment-refractory mental illness was feasible, well-tolerated, and associated with significant and substantial improvements in depression and psychosis symptoms and multiple markers of metabolic health.

The carbohydrate-insulin model: a physiological perspective on the obesity pandemic.

According to a commonly held view, the obesity pandemic is caused by overconsumption of modern, highly palatable, energy-dense processed foods, exacerbated by a sedentary lifestyle. However, obesity rates remain at historic highs, despite a persistent focus on eating less and moving more, as guided by the energy balance model (EBM). This public health failure may arise from a fundamental limitation of the EBM itself. Conceptualizing obesity as a disorder of energy balance restates a principle of physics without considering the biological mechanisms that promote weight gain. An alternative paradigm, the carbohydrate-insulin model (CIM), proposes a reversal of causal direction. According to the CIM, increasing fat deposition in the body-resulting from the hormonal responses to a high-glycemic-load diet-drives positive energy balance. The CIM provides a conceptual framework with testable hypotheses for how various modifiable factors influence energy balance and fat storage. Rigorous research is needed to compare the validity of these 2 models, which have substantially different implications for obesity management, and to generate new models that best encompass the evidence.

Type 2 Diabetes Mellitus: A Pathophysiologic Perspective.

Type 2 Diabetes Mellitus (T2DM) is characterized by chronically elevated blood glucose (hyperglycemia) and elevated blood insulin (hyperinsulinemia). When the blood glucose concentration is 100 milligrams/deciliter the bloodstream of an average adult contains about 5-10 grams of glucose. Carbohydrate-restricted diets have been used effectively to treat obesity and T2DM for over 100 years, and their effectiveness may simply be due to lowering the dietary contribution to glucose and insulin levels, which then leads to improvements in hyperglycemia and hyperinsulinemia. Treatments for T2DM that lead to improvements in glycemic control and reductions in blood insulin levels are sensible based on this pathophysiologic perspective. In this article, a pathophysiological argument for using carbohydrate restriction to treat T2DM will be made.

Carbohydrate-restricted diets and Type 1 diabetes mellitus: research considerations.

PURPOSE OF REVIEW: Type 1 diabetes mellitus (T1DM) is managed via careful control of blood glucose, exogenous insulin, diet, exercise, and other physiologic factors. Interestingly, the dietary recommendations for T1DM have had very little systematic research. Many clinical observations, as well as emerging research studies, have noted that a carbohydrate-restricted diet can lead to normalization of blood glucoses with reduction in hypoglycemic reactions among motivated individuals. RECENT FINDINGS: In this paper, we review observations of carbohydrate restriction and propose a series of studies to test two levels of dietary carbohydrate intake for the management of individuals affected by T1DM. We recommend that the studies start in otherwise healthy adults with hemoglobin A1c > 8%, and then progress to more complicated populations including children, those with secondary complications and/or good glycemic control. Larger, long-term studies would then address growth in children, and diabetic complications including cardiovascular outcomes. SUMMARY: Due to the clinical observations of improvements using carbohydrate-restricted nutrition for T1DM, we recommend that these types of studies addressing the level of dietary carbohydrate be urgently conducted.

A case study of overfeeding 3 different diets.

PURPOSE OF REVIEW: Quality or quantity of food has been at the heart of the diet debate for decades and will seemingly continue for many to come unless tightly controlled studies are conducted. To our knowledge, there has never been an overfeeding study comparing the effects of multiple diets. RECENT FINDINGS: This study reports a case study of an individual who ate 5800 Calories per day of 3 different diets for 21 days at a time. The 3 different diets were low-carb, low-fat, and very-low-fat vegan. The weight gain over 21 days was 1.3 kg for low-carb, 7.1 kg for low-fat, and 4.7 kg for very-low-fat vegan. SUMMARY: In this n-of-1 study, consuming 5800 Calories/day of 3 different diets for 21 days did not lead to the same amount of weight gain. Further research should be conducted on how the human body gains weight with an emphasis on how different foods affect physiology. If these findings are replicated, there would be many ramifications for obesity treatment and healthcare guidelines.

Using a low-carbohydrate diet to treat obesity and type 2 diabetes mellitus.

PURPOSE OF REVIEW: This study will provide a narrative review of the history of the clinical use of low-carbohydrate diets and give a practical example of how to implement a low-carbohydrate diet, with an emphasis on deprescribing medications. RECENT FINDINGS: Low-carbohydrate diets have been used since the late 19th century to treat obesity and type 2 diabetes mellitus (T2DM). Recently, clinical research has validated the use of low-carbohydrate diets for individuals affected by obesity and T2DM, and these diets are included in several national clinical guidelines. Because medications are commonly used to treat hypertension and T2DM, special consideration must be made to monitor and reduce these medications to avoid overmedication. Clinic visits and home monitoring of blood pressure and glucose levels are important tools to alert clinicians that a reduction in medication levels may be indicated. SUMMARY: Low-carbohydrate diets have been utilized clinically for many years to treat obesity and T2DM and can be used alongside effective monitoring to safely deprescribe dispensable medications for these diseases.

Application of nutrient essentiality criteria to dietary carbohydrates.

The purpose of the present review is to describe how human physiology at very low carbohydrate intakes relates to the criteria for nutritional essentiality. Although we did not limit ourselves to one particular type or function of carbohydrates, we did primarily focus on glucose utilisation as that function was used to determine the recommended daily allowance. In the general population, the human body is able to endogenously synthesise carbohydrates, and does not show signs of deficiency in the absence of dietary carbohydrates. However, in certain genetic defects, such as glycogen storage disease type I, absence of dietary carbohydrates causes abnormalities that are resolved with dietary supplementation of carbohydrates. Therefore, dietary carbohydrates may be defined as conditionally essential nutrients because they are nutrients that are not required in the diet for the general population but are required for specific subpopulations. Ketosis may be considered a physiological normal state due to its occurrence in infants in addition to at very low carbohydrate intakes. Although sources of dietary carbohydrates can provide beneficial micronutrients, no signs of micronutrient deficiencies have been reported in clinical trials of low-carbohydrate ketogenic diets. Nonetheless, more research is needed on how micronutrient requirements can change depending on the dietary and metabolic context. More research is also needed on the role of dietary fibre during a low-carbohydrate ketogenic diet as the beneficial effects of dietary fibre were determined on a standard diet and several studies have shown beneficial effects of decreasing non-digestible carbohydrates.

Treating binge eating and food addiction symptoms with low-carbohydrate Ketogenic diets: a case series.

BACKGROUND: Many patients with obesity and comorbid binge eating symptoms present with the desire to lose weight. Although some studies suggest that dietary restriction can exacerbate binge eating, others show dietary restriction is associated with significant reductions in binge eating. The effect of a particular type of dieting on binge eating, the ketogenic diet (a high fat, moderate protein, very low carbohydrate diet), is not known. CASE PRESENTATIONS: We report on the feasibility of a low-carbohydrate ketogenic diet initiated by three patients (age 54, 34, and 63) with obesity (average BMI 43.5 kg/m2) with comorbid binge eating and food addiction symptoms. All patients tolerated following the ketogenic diet (macronutrient proportion 10% carbohydrate, 30% protein, and 60% fat; at least 5040 kJ) for the prescribed period (e.g., 6-7 months) and none reported any major adverse effects. Patients reported significant reductions in binge eating episodes and food addiction symptoms including cravings and lack of control as measured by the Binge-Eating Scale, Yale Food Addiction Scale, or Yale-Brown Obsessive-Compulsive Scale modified for Binge Eating, depending on the case. Additionally, the patients lost a range of 10-24% of their body weight. Participants reported maintenance of treatment gains (with respect to weight, binge eating, and food addiction symptoms) to date of up to 9-17 months after initiation and continued adherence to diet. CONCLUSIONS: Although the absence of control cases precludes conclusions regarding the specific role of ketogenic diets versus other forms of dietary restriction, this is the first report to demonstrate the feasibility of prescribing a ketogenic diet for patients with obesity who report binge eating and food addiction symptoms. Further research should seek to reproduce the observed effects in controlled trials as well as to explore potential etiologies.