Eggs in a plant-based diet: Increased HDL and lower weight in metabolic syndrome

An abstract of the study entitled “Eggs as Part of a Plant-Based Diet. Beneficial Effects for Metabolic Syndrome (MetS)” was published in Current Developments in Nutrition. The authors report that adding eggs to a plant-based diet in people with metabolic syndrome (MS) was accompanied by an increase in HDL cholesterol, a decrease in body weight, and a partial “reversal” of the MS criteria (in ~45% of participants). This fits in with earlier randomized studies by the same group, where 2 eggs per day on a plant-based diet increased HDL and carotenoids without increasing LDL.

Background

• Metabolic syndrome (MS) is a common "collective" problem that increases the risk of cardiovascular disease and diabetes; nutrition is a key lever for its correction. Plant-based diets generally improve lipids and glycemia, but the place of eggs in such a diet remains a subject of debate due to the cholesterol in the yolk.
• An emerging body of evidence is “eggs + PBD (plant-based diet)”. In a randomized crossover study in people with MS, adding whole eggs to PBD for 4 weeks increased HDL-cholesterol, increased large HDL particles, and choline and zeaxanthin levels, without worsening LDL/TG and with a trend toward weight loss. Separately, no increase in inflammation/oxidative stress was shown.
• In the broader egg literature, reviews and meta-analyses in recent years have found no increase in CVD risk in the general population with moderate egg consumption, and the effect on lipids is often neutral or with a small increase in HDL. In a number of observational studies, higher frequency of egg consumption has been associated with a lower likelihood of MS.
• Why eggs may “work” in PBD for MS: They are a dense source of high-quality protein, choline (important for lipid metabolism and the liver), and carotenoids (lutein/zeaxanthin), which are transported specifically by HDL and may favorably affect its particle profile. Against the background of a whole plant plate, the effect of yolk on LDL, according to RCTs, was not observed.
• Additional trials are underway. Clinical trials comparing “vegan diet vs. vegan + 2 eggs/day” in adults with cardiometabolic risk assessment have been registered – i.e. the question is being actively tested in a standardized design.

In summary: The context suggests that moderate inclusion of eggs in a predominantly plant-based diet in people with MS may maintain HDL and nutrient status without worsening atherogenic lipids - but full-text publications and independent replications of the 2025 findings are needed.

What exactly was studied?

The material was published as a conference abstract (ASN Nutrition 2025): a short report on the results of an intervention in people with MS who followed a plant-based diet (PBD) with the inclusion of eggs. According to the abstract, on such a diet, HDL-C increased, weight decreased, and the set of diagnostic criteria for MS "unfolded" in ~45% of participants. That is, some people no longer met the threshold for SPB, waist, lipids or glycemia. The full protocol and tables are not provided in the abstract (this is a feature of the format), but a general conclusion about the benefits of eggs in the context of PBD is indicated.

For context, in a 2022 randomized crossover trial, the same authors compared a 2-egg-spinach breakfast versus a plant-based “egg substitute” on PBD in people with MS. After 4 weeks, the eggs diet resulted in higher HDL, more large HDL particles, higher choline and zeaxanthin, and lower body weight — without worsening LDL, TG, glucose, or blood pressure. This supports both the biological plausibility and replicability of the current observations.

Why is this important?

• Plant-based diet ≠ mandatory egg-free diet. In real “flexitarian” practice, eggs can fill choline, carotenoids (lutein/zeaxanthin) and high-quality protein deficiencies while remaining within the confines of a predominantly plant-based plate. In the context of PBD, this can improve the lipid profile due to HDL and nutrient biomarkers.
• About "metabolic syndrome". PBD itself usually reduces total and LDL cholesterol, improves glycemia and body weight; adding eggs, according to the data, does not "break" this effect and can even enhance some indicators (HDL, carotenoids) - provided that the diet otherwise remains whole food and moderate in saturated fats.

What does this mean in practice?

• If you are on a plant-based diet and have MS, including 1-2 eggs per day (usually boiled/poached, with vegetables, whole grains) can support HDL and nutrient status (choline, carotenoids) - without worsening LDL, as long as the overall diet remains balanced. The weight loss data in the abstract and the 2022 RCT are consistent.
• Eggs are especially appropriate as part of a whole plant-based plate (vegetables, legumes, whole grains, nuts, fruits) and as a replacement for ultra-processed fat/sugar sources.

Important Disclaimers and Limitations

• The current publication is a short abstract: without full methodology, numbers and statistics, interpretation is limited. We await the full article with data.
• Conflicts of interest in related work of the group were indicated (funding from Egg Nutrition Center for co-authors of reviews/studies); this does not invalidate the results, but requires independent replication.
• Eggs are not a panacea. In case of familial hypercholesterolemia, allergies, specific dietary indications, decisions are made with a doctor/nutritionist. The balance of saturated fats and the overall nutritional "portfolio" are still more important than a single product.

How to Embed Eggs in PBD "Without Harm"

• Focus on whole foods: vegetables (including leafy greens and eggs), legumes, whole grains, nuts/seeds, olive oil; eggs are an accent, not the center of the diet.
• Choose cooking methods without excess fat (boiled, poached); combine with sources of fiber and unsaturated fats.
• Monitor laboratory parameters (lipid panel, glucose), especially if there were any violations before.

Sources: Abstract Current Developments in Nutrition (May 2025, DOI 10.1016/j.cdnut.2025.106145 ).