What Are the Downsides of the Paleo Diet?

November 24, 2025 •

3 min read

A study on overweight adults found that adherence to the paleo diet was challenging and had one of the lowest long-term retention rates compared to other diets. Understanding what are the downsides of the paleo diet is crucial before adopting this restrictive eating pattern for the long term.

Quick Summary

The paleo diet, which eliminates whole grains, legumes, and dairy, risks nutritional deficiencies in calcium, fiber, and B vitamins. Significant drawbacks also include higher cost, social isolation, potential for high saturated fat intake, and long-term sustainability concerns.

Key Points

Nutrient Deficiencies: Eliminating entire food groups like dairy, grains, and legumes can lead to deficiencies in essential nutrients, including calcium, vitamin D, and fiber.
Increased Cost: The paleo diet is often more expensive due to its emphasis on fresh, non-processed foods, grass-fed meats, and high-quality produce.
Social Isolation: The strict nature of the diet can make social situations like dining out and family gatherings challenging and isolating.
Gut Health Concerns: The exclusion of whole grains and legumes can reduce fiber intake and negatively alter beneficial gut bacteria over time.
Sustainability Issues: High consumption of animal products, particularly red meat, gives the paleo diet a higher environmental footprint compared to more plant-based alternatives.
Difficult Long-Term Adherence: The restrictive nature makes the paleo diet hard to maintain, with studies showing lower retention rates than other diets.
Potential for High Saturated Fat Intake: Without careful selection of lean cuts, the diet can result in high saturated fat consumption, which is linked to increased cardiovascular risk.

The paleo diet, often called the 'caveman diet', mimics the eating patterns of early humans before agriculture. It focuses on foods like lean meats, fish, fruits, and vegetables while excluding processed items, grains, dairy, and legumes. While beneficial for some in the short term, this approach has considerable disadvantages.

Nutritional Deficiencies and Health Risks

Excluding nutrient-rich food groups in the paleo diet can lead to several deficiencies. Avoiding dairy removes primary sources of calcium and vitamin D, vital for bone health, which could increase the risk of osteoporosis without careful planning or supplementation. Eliminating grains and legumes can reduce fiber for digestion and a healthy gut microbiome, potentially impacting gut bacteria and leading to digestive problems. Research suggests long-term paleo dieters may have different gut bacteria. A focus on meat can increase saturated fat intake, linked to higher LDL cholesterol and increased risk of heart disease.

Social and Practical Challenges

The diet's restrictions create lifestyle difficulties. Relying on fresh produce and quality proteins makes this diet more expensive, especially when avoiding staples like grains and legumes. The diet can complicate social events involving food, potentially leading to isolation. Many find the strictness and cost unsustainable, sometimes called 'diet fatigue'.

Environmental Impact

The paleo diet's emphasis on animal products raises environmental concerns. Livestock farming contributes significantly to greenhouse gas emissions. A paleo diet generally has a higher carbon footprint than diets with more plant-based foods and meat production requires more resources than plant-based protein sources.

Paleo Diet vs. Mediterranean Diet: A Comparison


Feature	Paleo Diet	Mediterranean Diet
Included Foods	Meat, fish, eggs, fruits, vegetables, nuts, seeds, healthy fats	All of the above, plus whole grains, legumes, dairy, and olive oil
Excluded Foods	Grains, legumes, dairy, processed sugars, refined oils, and most processed foods	Highly processed foods and added sugars, with limited red meat and saturated fats
Sustainability	Lower overall sustainability due to higher emphasis on meat production	Higher overall sustainability due to lower consumption of animal products
Cost	Generally higher cost due to emphasis on organic and grass-fed products	Typically more affordable due to inclusion of budget-friendly grains and legumes
Research Backing	Limited long-term research, results mixed, short-term benefits often linked to avoiding processed foods	Strong, long-term evidence supporting heart health and blood sugar benefits
Adherence	Low long-term retention rates due to restrictive nature	Generally higher adherence due to flexibility and variety

Acknowledging the Limitations and Unknowns

Long-term clinical research on the paleo diet is limited. While short-term benefits like weight loss are seen, they may stem more from avoiding processed foods than excluding specific groups. The diet's premise about human evolution and food is also debated.

Conclusion

While promoting whole foods, the paleo diet has significant drawbacks, including potential deficiencies in calcium, vitamin D, and fiber. High costs and social difficulties impact adherence. Its reliance on meat also raises environmental concerns. A less restrictive approach, like the Mediterranean diet, may offer similar benefits with better sustainability and adherence. Consult a healthcare professional before starting the paleo diet, especially with existing health conditions.

{Link: NCBI PMC https://pmc.ncbi.nlm.nih.gov/articles/PMC7351840/}

Frequently Asked Questions

The diet’s restriction of dairy, grains, and legumes can cause deficiencies in calcium, vitamin D, fiber, and B vitamins, potentially impacting bone health and digestion over time.

Yes, focusing on fresh, organic produce, and often higher-priced grass-fed meats and fish makes the paleo diet more costly than a standard diet based on processed foods, grains, and legumes.

Some people experience initial digestive issues like diarrhea or constipation due to the significant change in fiber intake from eliminating grains and legumes. Long-term adherence has also been linked to unfavorable gut bacteria changes.

No, studies indicate that the heavy emphasis on animal products, particularly red meat, gives the paleo diet a significantly higher carbon footprint compared to diets with a greater proportion of plant-based foods.

Yes, research suggests the restrictive nature of the diet makes long-term adherence difficult, with some studies showing high dropout rates compared to less restrictive diets.

Some versions of the diet can be high in saturated fats from abundant meat and animal products. Some studies also show unfavorable gut bacteria changes linked to heart disease risk markers, though more long-term research is needed.

Individuals with chronic kidney disease, osteoporosis, a history of disordered eating, or athletes with high carbohydrate needs should consult a healthcare professional before starting this diet due to its restrictive nature and potential health risks.