- The quality of low-carb and low-fat diets may be more crucial for heart health than merely the amounts of fat and carbohydrates consumed.
- Health-conscious versions of low-fat and low-carb diets that prioritize whole grains, plant-based foods, and unsaturated fats are linked to a reduced risk of coronary heart disease.
- Conversely, unhealthy variations of these diets, which are high in animal fats, refined carbohydrates, and proteins, correspond to an increased risk of coronary heart disease.
Understanding the impact of food quality within low-carbohydrate and low-fat diets may play a pivotal role in reducing the risk of heart disease, beyond just monitoring fat and carb quantities.
Recent findings demonstrate that healthier forms of low-carb and low-fat diets that emphasize whole grains, unsaturated fats, and plant-based foods result in significantly lower rates of coronary heart disease (CHD).
“Our research underscores the importance of food quality in these diets, not merely focusing on reducing carb or fat intake,” stated Zhiyuan Wu, a postdoctoral research fellow at Harvard T.H. Chan School of Public Health and the lead author of the study, in a press statement.
“The effectiveness of low-carb and low-fat diets in mitigating the risk of CHD has been extensively debated, with previous studies yielding mixed results. Merely concentrating on nutrient composition without considering food quality may not yield significant health benefits,” Wu elaborated.
The study analyzed data from nearly 200,000 participants over three major studies, collecting information from more than 30 years of follow-up.
Throughout this period, 20,033 cases of coronary heart disease were reported.
Participants’ dietary habits were assessed through food frequency questionnaires.
The significance of diet quality in low-carb and low-fat diets has remained largely unexplored until now. This study represents one of the most comprehensive analyses concerning diet quality, metabolic profiles, and CHD risk.
The researchers concluded that unhealthy low-fat and low-carb diets, rich in animal fats, protein, and refined carbohydrates, were associated with heightened risks of coronary heart disease.
Oana Penciu, MD, a cardiologist at Keck Medicine of USC, who was not involved in the study, remarked on the findings’ significance.
“It’s not surprising, but it confirms what we’ve long awaited. The age-old debate over ‘low-carb’ versus ‘low-fat’ diets has often been clouded by conflicting research. This study clarifies that food quality is the crucial variable,” Penciu informed Healthline.
“These results align with prior trials such as CORDIOPREV and DIETFITS, which showed that healthier iterations of both diets—focusing on plant-based proteins, unsaturated fats, and whole grains—offer similar protective benefits. The essential message is clear: the source of food is far more important than its label,” she continued.
In the U.S., both low-carb and low-fat diets are prevalent, but Penciu noted that many individuals overlook healthy practices within these dietary frameworks.
“A gap in public understanding persists. While low-carb and low-fat diets are widely followed, the unhealthy variants—heavy in refined carbohydrates or animal fats—are still common,” Penciu stated.
“A low-fat diet laden with sugar can be just as detrimental as a low-carb plan rich in saturated fat. A low-fat cookie remains just that—a cookie. The inconsistencies in past studies have likely fueled confusion, as definitions of diets have varied widely,” she elaborated.
In the United States, heart disease is the
Every 34 seconds, a person in the U.S. succumbs to cardiovascular disease.
Coronary heart disease is the most prevalent type, accounting for 371,506 deaths in 2022.
Maintaining a balanced diet plays a crucial role in lowering the risk of heart disease.
“Diet is a vital element in maintaining cardiometabolic health. What you consume directly impacts cardiovascular risk factors such as blood pressure, cholesterol levels, and body weight,” explained Cheng-Han Chen, MD, a board-certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA, who was not involved in the study.
“Moreover, the quality of your diet influences the level of inflammation in your body, further impacting your heart disease risk,” he added.
Chen recommends adopting a heart-friendly diet rich in plant-based foods, nuts, whole grains, and lean proteins, while minimizing sodium, saturated fats, and processed carbohydrates.
“For optimal cardiovascular health, we typically suggest a low-fat diet. This study clarifies that the macronutrient content of one’s diet is also crucial, particularly in limiting refined carbohydrates,” he advised.
When choosing between low-fat and low-carb diets, experts agree that both have their advantages.
“Each dietary approach possesses merits for cardiometabolic health. For a relatively normal-weight patient with high cholesterol, a low-fat diet might be more advantageous,” said Mir Ali, MD, a bariatric surgeon and medical director at the MemorialCare Surgical Weight Loss Center in Fountain Valley, CA, who was also not involved in the study.
“On the other hand, if weight loss is the primary goal, reducing carbohydrate intake can be beneficial. Recommendations must be personalized based on a thorough clinical assessment,” he pointed out.
Ali suggests initiating minor adjustments, such as swapping out one unhealthy food at a time, to foster a seamless transition. Major dietary changes can be challenging to sustain long-term.
Penciu advises focusing on food balance instead of adhering to a specific diet.
“Don’t overly complicate things; just prioritize whole foods. Create balanced meals featuring vegetables, lean proteins like chicken, fish, eggs, beans, or tofu, alongside whole grains or starchy vegetables like quinoa, brown rice, or sweet potatoes. Add some healthy fats (such as olive oil, avocado, nuts, or seeds) to ensure meals are filling,” Penciu recommended.
“Keep the flavors simple with herbs, spices, or a dash of lemon instead of sugary sauces, avoid heavily processed foods when you can, and substitute sugary beverages with water or tea. Aim for gradual improvements rather than perfection. Consistent, small changes can lead to significant results,” she concluded.
