New research debunks myths surrounding eggs and obesity, showing how moderate consumption supports health, while highlighting the best cooking methods for maximum nutritional benefits.
Study: Relationship between egg consumption and obesity risk: a comprehensive review: EGG CONSUMPTION AND OBESITY. Image credit: MasAnyanka / Shutterstock
In a recent review published in the journal Poultry Scienceresearchers conducted a comprehensive review to clarify whether frequent egg consumption may increase the risk of obesity in healthy people. They reviewed two decades of nutritional literature between 2002 and 2022 and found that most egg-derived nutrients (lecithins, lipoproteins, and unsaturated fatty acids) were not associated with an increased risk of obesity. Surprisingly, most research shows that these nutrients reduce the likelihood of obesity by regulating lipid metabolism. The review also noted that individual responses to dietary cholesterol vary, with some individuals classified as “high responders” who may experience significant changes in cholesterol levels, underscoring the importance of individualized dietary advice.
In particular, the choice of cooking method was found to substantially alter the nutritional composition of eggs, thus significantly affecting their physiological effects on human health. In particular, soft-boiled eggs were determined to be the best method, retaining the most beneficial nutrients compared to hard-boiled or fried eggs. In summary, seven to eight eggs per week were not associated with an increased risk of obesity in healthy people.
Background
Obesity is one of the major public health problems of modern society, with the World Health Organization (WHO) estimating that one in eight people live with the condition. The condition is characterized by abnormal weight (body mass index [BMI] > 30). It is associated with many chronic and potentially life-threatening diseases, including cardiovascular disease (CVD), type 2 diabetes (T2D), liver disease and some cancers.
Alarmingly, the prevalence of obesity is rising to unprecedented levels, with current projections estimating that more than half of the world’s population will be living with the chronic disease by 2035. Previous research has identified suboptimal health behaviors, particularly diet, as key factors that contribute to obesity.
Eggs are an everyday, affordable and widely consumed source of high-quality protein, nutrients and essential amino acids. Unfortunately, eggs are high in cholesterol (~186 mg per large egg), a notable risk factor for obesity. While several studies have suggested that moderate egg consumption (1-2 eggs per day) does not significantly affect circulating cholesterol levels, there is considerable variation in individual responses, with some individuals metabolizing dietary cholesterol more efficiently than others. The lack of comprehensive reviews on the topic leaves clinicians, dietitians, and consumers uncertain about the health effects of egg-derived nutrients and their individual or additive risks of obesity.
About the review
The present review aimed to reveal the relationship between egg consumption (in healthy people) and obesity incidence, focusing on the individual and cumulative effects of the various egg-derived nutrients, thereby informing future dietary guidelines on the pros and cons of consumption. of eggs (including daily/weekly recommended intake guidelines). Screening of publications was performed through a customized keyword search in three online repositories of scientific literature – Scopus, PubMed and Google Scholar. These repositories were queried for relevant articles, publications, reviews or meta-analyses between 2002 and 2022.
Identified publications were screened to eliminate duplicates, non-English publications, abstracts, case reports, or publications presenting incomplete information. The review then compiled included publications that briefly define obesity and list its health risks, global consumption trends, current prevalence, and future projections. It then identifies and compiles data on egg-derived nutrients commonly implicated in obesity research, particularly cholesterol, lecithin, fatty acids, protein, vitamins and minerals.
Review of findings
The review identified cholesterol as the most controversial nutrient in the egg obesity debate, but emphasized that the endogenous regulation of cholesterol consumed by the healthy human body is more than sufficient to explain moderate egg consumption (~1-2 eggs per day ). Previous research has failed to demonstrate a specific relationship between moderate egg consumption and obesity or overweight (BMI > 25). These conclusions are supported by summary statistics, which reveal that <10 eggs per week do not significantly alter the risk of obesity.
In contrast, eggs are one of the healthiest sources of protein and essential amino acids and also contain significant amounts of vitamins and minerals, underscoring the overall health benefits. “When weekly intake is between seven and eight, people with a normal weight BMI <25 are not at risk of being overweight or obese and maximize their nutrient intake," the authors said.
Recent research shows that cooking methods can change the nutrient profiles of eggs, with frying and overheating resulting in nutrient losses. Soft-boiled eggs are recommended as the most nutritious preparation method, preserving both lipids and bioactive nutrients. However, undercooked egg whites can present risks due to anti-nutritional factors and bacterial contamination. Current dietary recommendations consider hard-boiled or soft-boiled eggs to be the healthiest, although additional targeted research is needed to confirm these assumptions.
conclusions
This comprehensive review highlights the lack of evidence linking frequent but moderate egg consumption with increased risk of obesity. The limited literature investigating egg cholesterol content with adverse health effects reveals that the human body’s endogenous cholesterol regulatory mechanisms are sufficient to explain the excess cholesterol derived from the egg. On the contrary, eggs are one of the healthiest sources of protein, essential amino acids and micronutrients beneficial to human health.
In summary, the health benefits of eggs make them an ideal addition to a person’s daily diet. While people with pre-existing cholesterol conditions (high reactivity or high reference values) may need to limit their weekly egg consumption, healthy people should not be concerned with <10 eggs per week. Further research is needed to explore how cultural dietary patterns and egg consumption influence obesity risk, as dietary habits vary significantly between populations. Additional research is needed to identify the best cooking methodologies for optimal absorption of egg nutrients.
