Evidence that supports the prescription of low-carbohydrate high-fat diets: a narrative review

Abstract

Low-carbohydrate high-fat (LCHF) diets are a highly contentious current topic in nutrition. This narrative review aims to provide clinicians with a broad overview of the effects of LCHF diets on body weight, glycaemic control and cardiovascular risk factors while addressing some common concerns and misconceptions. Blood total cholesterol and LDL-cholesterol concentrations show a variable, highly individual response to LCHF diets, and should be monitored in patients adhering to this diet. In contrast, available evidence from clinical and preclinical studies indicates that LCHF diets consistently improve all other markers of cardiovascular risk—lowering elevated blood glucose, insulin, triglyceride, ApoB and saturated fat (especially palmitoleic acid) concentrations, reducing small dense LDL particle numbers, glycated haemoglobin (HbA1c) levels, blood pressure and body weight while increasing low HDL-cholesterol concentrations and reversing non-alcoholic fatty liver disease (NAFLD). This particular combination of favourable modifications to all these risk factors is a benefit unique to LCHF diets. These effects are likely due in part to reduced hunger and decreased ad libitum calorie intake common to low-carbohydrate diets, allied to a reduction in hyperinsulinaemia, and reversal of NAFLD. Although LCHF diets may not be suitable for everyone, available evidence shows this eating plan to be a safe and efficacious dietary option to be considered. LCHF diets may also be particularly beneficial in patients with atherogenic dyslipidaemia, insulin resistance, and the frequently associated NAFLD.

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

“…Discrepancy exists even within the low‐CHO‐diet studies between interventions that purposefully minimized or reduced saturated fat and those that did not. The effect(s) of dietary saturated fat on cardiovascular disease mortality and all‐cause mortality remain inconclusive, with some evidence suggesting reduced cardiovascular disease risk with low‐CHO high‐fat diets . Regardless, the common prescription to include dietary fat from mostly whole‐food sources might offer some natural protection against excessive intakes of any specific fatty acid.…”

“…The effect(s) of dietary saturated fat on cardiovascular disease mortality and all-cause mortality remain inconclusive, 76 with some evidence suggesting reduced cardiovascular disease risk with low-CHO high-fat diets. [77][78][79] Regardless, the common prescription to include dietary fat from mostly whole-food sources might offer some natural protection against excessive intakes of any specific fatty acid. Many of the low-CHO diet foods that are recognized for their high saturated fat content also tend to contain a high, if not higher, monounsaturated fat content.…”

Ketogenic Ratio Determines Metabolic Effects of Macronutrients and Prevents Interpretive Bias

“…On the other hand, the low-carbohydrate diets that are high in fat have a number of metabolic advantages: for instance, they facilitate increase energy expenditure by increasing thermogenic effects and excretion of ketone bodies (104). …”

Ketogenic diet and its impact on mental processes of working population

“…Most energy in a KD comes from fat with moderate protein intake and minimal carbs intake -one of the strictest ratios being 90 : 2 : 8 (Oliveira et al, 2017). Most common rule implies 20 to 50 grams of carbs daily (Noakes et al, 2017). This induces ketosis: the liver starts producing ketone bodies (KB) as a metabolite of fats, glucose levels settle down and its concentration normalizes; insulin levels decrease, plasma pH decreases slightly as well (Oliveira et al, 2017).…”

“…KD surpasses the benefits of high carbohydrate diets (Chang et al, 2017), for example in cancer, diabetes, cardiovascular diseases (Bazzano et al, 2015), AD and multiple sclerosis (Erickson et al, 2017). It's efficient for weight loss (Yancy et al, 2010, Bueno et al, 2013, appetite regulation, glycaemic control (Volek et al, 2009), stabilisation of hyperinsulinemia, improving insulin sensitivity and normalizing blood lipid profiles (Chang et al, 2017, Noakes et al, 2017, Oliveira et al, 2017. KD has been studied as adjuvant therapy in brain neoplasms.…”