Additional studies have suggested that low-carbohydrate diets may even increase overall mortality risk. Others have linked certain restrictive eating patterns to disruptions in gut health and metabolic balance
A growing body of research is raising fresh concerns about the long-term health impact of high-fat, low-carbohydrate diets such as the ketogenic diet, with new studies linking them to increased risks of cancer, heart disease and nutritional deficiencies.
While keto-style diets have surged in popularity for their ability to deliver rapid weight loss, scientists warn that their high fat content may come with serious unintended consequences. A recent preclinical study from the University of Utah found that elevated lipid levels — a hallmark of such diets — could fuel the growth of aggressive cancers, including triple-negative breast cancer.
Researchers at the Huntsman Cancer Institute discovered that cancer cells appear to rely heavily on fats for growth. Their findings suggest that even in the absence of other obesity-related factors like high blood sugar, excess lipids alone were enough to accelerate tumour development in animal models. Conversely, lowering lipid levels slowed tumour progression.
Experts say this raises important questions for cancer patients and survivors, particularly those considering high-fat diets for weight management. Although weight loss can be beneficial, the metabolic changes triggered by fat-heavy diets may counteract those gains in certain cases.
Concerns are not limited to cancer. Cardiovascular specialists have also warned that low-carb, high-fat (LCHF) diets may negatively impact heart health. A study from the University of British Columbia found that individuals following such diets had significantly higher levels of LDL, often referred to as “bad” cholesterol, and apolipoprotein B — a key marker associated with increased risk of heart disease.
Published in JACC: Advances, the research showed that over time, participants on LCHF diets experienced a higher incidence of major adverse cardiovascular events, including heart attacks and strokes, compared to those on standard diets.
Medical experts caution that while these diets may produce short-term results, they are often not sustainable and can lead to imbalances in essential nutrients. Fad diets, including keto, paleo and extreme low-carb regimens, typically focus heavily on one macronutrient while neglecting others, potentially leading to deficiencies and long-term health complications.
Additional studies have suggested that low-carbohydrate diets may even increase overall mortality risk. Others have linked certain restrictive eating patterns to disruptions in gut health and metabolic balance.
Nutritionists emphasise that there is no one-size-fits-all approach to weight loss. Instead, they recommend balanced, sustainable eating patterns that include a mix of carbohydrates, proteins and healthy fats. Diets rich in fruits, vegetables and plant-based foods — such as the Mediterranean diet — are widely regarded as safer and more effective for long-term health.
Ultimately, experts advise against following diet trends without professional guidance. Consulting a qualified nutritionist or healthcare provider can help ensure that dietary choices support both weight management and overall wellbeing.
As research continues to evolve, the message remains clear: quick fixes may deliver fast results, but long-term health depends on balance, moderation and informed choices.
