Low-carb eating has been popularized by many diet books. As is the situation with many diet categories, there is no agreed-on or fixed definition of a low-carbohydrate diet. One suggestion is that a diet with a carbohydrate
intake below 45% of total calories would qualify as low-carbohydrate. The original
Atkins diet called for replacing carbohydrates with an unrestricted intake of
meat and dairy.

A 2016 meta-analysis of randomized controlled trials assessed the effects of low-fat
vs. low-carbohydrate diets on weight loss and risk factors of CVD. The low-carbohydrate
diet was defined in accordance with the Atkins diet, or carbohydrate intake
of <20% of total energy intake. The dietary goal for the low-fat diets was typical,
with <30% of total energy as fat; however, a few studies had as low as 10% of
total energy as fat. Compared with participants on low-fat diets, participants on
low-carbohydrate diets experienced a greater reduction in body weight but a greater
increase in HDL-C and unhealthy LDL-C. The study authors suggest that the
beneficial changes of low-carbohydrate diets must be weighed against the possible
detrimental effects of increased LDL-C.

Although good evidence from long-term studies is not available, an Atkins style high-protein, high fat, low-carbohydrate diets
without calorie restriction can be expected to cause the adverse long-term health
effects of the excessive saturated fat and protein found in typical American diets. In 2018, Professor Maciej Banach presented a study at the European Society of Cardiology, stating: “We found that people who consumed a low carbohydrate diet
were at greater risk of premature death. Risks were also increased for individual
causes of death, including coronary heart disease, stroke, and cancer. These diets
should be avoided.” The study found that compared to those in the highest carbohydrate
group, those who ate the lowest carbohydrates had a 32% higher risk of
all-cause death over six years, and risks of death from heart disease and cancer were
increased by 51% and 35%, respectively. Banach said: “Low carbohydrate diets
might be useful in the short term to lose weight, lower blood pressure, and improve
blood glucose control, but our study suggests that in the long-term they are linked
with an increased risk of death from any cause, and deaths due to cardiovascular
disease, cerebrovascular disease, and cancer.” In considering the reason for the difference
in risk, he stated that: “The reduced intake of fiber and fruits and increased
intake of animal protein, cholesterol, and saturated fat with these diets may play a

Newer, presumably healthier, versions of low carb eating, such as the Eco-Atkins
diet studied by Jenkins and colleagues, emphasized consumption of high-protein
plant rather than animal foods. A study of the Eco-Atkins diet that featured calorie
restriction and plant-based low carbohydrate foods that included soy protein and
nuts found that bodyweight declined and total cholesterol, LDL-C, triglycerides,
and other cardiovascular biomarkers improved.

The Portfolio Diet is a similar diet developed by the same team of researchers. It
is based on the theory that putting together four dietary components, each shown to
lower cholesterol by 5% to 10%, will be additive and maximize their effect. Based
on a 2,000-calorie daily diet, the daily servings are:

• Plant protein: 50 grams a day, from soy foods such as tofu, soy milk, and soy
meat analogs, plus legumes like beans, peas, and lentils
• Nuts: 45 grams a day of tree nuts of all kinds, including peanuts, as well as
nut butters
• Viscous soluble fiber: 20 grams a day, from oats, barley, eggplant, okra,
apples, berries, oranges, and psyllium
• Plant sterols: 2 grams a day, from fortified foods such as margarine spreads,
juices, and yogurt, or from supplements with and without monounsaturated
fats providing 26% of energy

A meta-analysis of seven clinical trials of the Portfolio Diet found that after four to
24 weeks, LDL-C declined by 27%. The trials used a National Cholesterol Education
Program (NCEP) diet with moderately low total fat (30% of calories) and
low-saturated-fat (7% of calories) as a baseline comparison. Those on the NCEP
diet reduced LDL-C by just 10%. The study authors concluded that the plant-based
Portfolio Diet reduced the estimated 10-year risk of heart disease by 13% and that
the 33% reduction in LDL-C from the Portfolio Diet was a result comparable to that
from statin therapy.

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.