Currently fashionable low-carbohydrate and paleo diets typically are low in refined
grains and added sugars but feature relatively high quantities of red and processed
meat and saturated fat. A meta-analysis of randomized controlled trials (RCTs)
found that in weight-loss trials, unlike metabolic studies where all eaten food is
carefully controlled, low-carbohydrate interventions led to significantly greater
weight loss than did low-fat dietary interventions.
Recent formulations of ketogenic diets limit protein to amounts needed to maintain
muscle mass, eliminate sugars and refined carbohydrates, and restrict total carbohydrates
to 80 to 200 calories a day. A meta-analysis found that individuals consuming
very-low-carbohydrate ketogenic diets (less than 200 calories of carbohydrates/
day) achieved better long-term body weight loss than individuals assigned to a conventional
low-fat diet with less than 30% of calories from fat.
Because low-carb diets are low in calories, they are effective for short-term use and
improve some metabolic biomarkers, but with long-term use, they may increase
health risk. For example, a meta-analysis that found a greater weight loss in subjects
on low carbohydrate diets than those on low-fat diets found that although
the low carb dieters had favorable changes in HDL-cholesterol and triglyceride
levels, they had unfavorable increases in the LDL-cholesterol levels that are more
significant for cardiovascular health. The study authors concluded the beneficial
changes of low-carbohydrate diets must be weighed against the possible detrimental
effects of increased LDL-cholesterol.
A systematic review of 17 studies found that the risk of all-cause mortality among
those with a high low-carbohydrate score was elevated by 30%. A meta-analysis
published in Lancet Public Health found that low carbohydrate diets with less than
50% to 55% energy from carbohydrate were associated with increased all-cause
mortality unless their protein and fat was plant-based. The excessive protein in
low-carb diets has the potential to contribute to kidney and liver damage. They
cannot be considered heart-healthy for long-term use.
This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel