Did your mother always say breakfast was the day’s most important meal? As it turns out, she was right – but with a catch. New research suggests that when it comes to our morning meal, both portion size AND nutritional quality play crucial roles in maintaining good health, especially for older adults at risk for heart disease

While research has shown that skipping breakfast is linked to poorer overall diet quality and higher cardiometabolic risk, Spanish researchers explored an understudied area: how both the calorie intake and dietary quality of breakfast might affect cardiovascular health over time

“Promoting healthy breakfast habits can contribute to healthy ageing by reducing the risk of metabolic syndrome and associated chronic diseases, thereby improving quality of life,” says Karla-Alejandra Pérez-Vega, a researcher at Hospital del Mar and CIBER for Obesity and Nutrition, in a statement

How breakfast influences overall health

The investigation was part of the larger PREDIMED-Plus trial, which studies the effects of Mediterranean diet and lifestyle interventions on cardiovascular health

The study included 383 adults aged 55-75 who participated in the Hospital del Mar Research Institute trial in Barcelona. All participants had metabolic syndrome, a cluster of conditions including high blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol levels that together increase the risk of heart disease, stroke, and diabetes. They were also following a weight-loss lifestyle intervention based on the Mediterranean diet

Researchers tracked these individuals’ breakfast habits and health markers for three years. They discovered something fascinating: people who ate either too little (less than 20% of their daily calories) or too much (more than 30%) at breakfast tended to fare worse than those who hit the sweet spot of 20-30% of their daily caloric intake during their morning meal

By the study’s end, the differences were striking. Compared to the Goldilocks group, who ate just right, participants who consumed too little or too much at breakfast showed higher body mass index (BMI) measurements and larger waist circumferences. Their blood work also revealed higher levels of triglycerides (a type of fat found in blood) and lower levels of “good” HDL cholesterol

Quality also plays a key role

But quantity wasn’t the only factor that mattered. Quality played an equally important role. Participants whose breakfasts scored low on nutritional quality – regardless of size -showed similar negative health trends. They, too, had larger waist measurements, less favourable blood fat profiles, and perhaps most surprisingly, decreased kidney function compared to those who ate more nutritionally balanced morning meals

Researchers used the Meal Balance Index to assess breakfast quality. The index scores meals based on nine nutritional components. It uses Acceptable Macronutrient Distribution Ranges for proteins and fats, Daily Values for fibre, potassium, calcium, and iron, and World Health Organization recommendations for added sugars, saturated fats, and sodium. Each component receives a score from 0 to 100, with scores for potassium and saturated fat weighted double in the final calculation. Higher scores indicate better nutritional quality

These findings, published in The Journal of Nutrition, Health and Aging, are particularly relevant for older adults trying to manage or prevent heart disease. While previous research has established that eating breakfast is better than skipping it, this study suggests that simply eating any breakfast isn’t enough – both portion size and nutritional quality need careful consideration

The ‘perfect’ breakfast

What does an ideal breakfast look like? The study suggests aiming for the 20-30% sweet spot of daily calories. For someone eating 2,000 calories per day, that would mean a breakfast between 400 and 600 calories. Quality-wise, think balanced meals incorporating whole grains, lean proteins, healthy fats, and fruits or vegetables while limiting processed foods high in added sugars and unhealthy fats

“Breakfast is the most important meal of the day, but what and how you eat it matters. Eating controlled amounts—not too much or too little—and ensuring good nutritional composition is crucial,” says Álvaro Hernáez, a researcher at the Hospital del Mar Research Institute, CIBER for Cardiovascular Diseases (CIBERCV), and professor at the Blanquerna Faculty of Health Sciences at Ramon Llull University. “Our data show that quality is associated with better cardiovascular risk factor outcomes. It’s as important to have breakfast as it is to have a quality one.”