OPINION: Personally, I need breakfast. Almost every morning, I wake up early feeling hungry, and it’s only once I banish my morning hunger that I’m ready to fire. By mid-morning, I take a break and enjoy a snack.

I’ve used a personal anecdote because it’s likely that eating breakfast – or skipping it – may simply reflect a personal preference for timing food intake. Not everyone enjoys eating first thing in the morning. But your first choice of foods may contribute to an overall healthy diet.

An important note of caution first: any study of breakfast’s benefits is fraught with difficulty because breakfast studies are often funded by the makers of ready-to-eat breakfast cereals. That doesn’t necessarily make their findings invalid, but it means we need to look carefully at how the studies are constructed and the way their findings may have been interpreted.

Nutritional benefits

It’s logical to assume that eating three meals a day (rather than two) makes it easier to meet the body’s needs for many nutrients. But such assumptions depend on what you include in each meal and whether particular nutrients likely to be consumed at breakfast are marginal in your diet in the first instance.

Many ready-to-eat breakfast cereals emphasise their content of added vitamins (usually thiamin, riboflavin, or niacin), even though these are not commonly deficient in diets of people living in developed countries. So studies showing higher intakes of these vitamins in people who consume these products (generally funded by the makers of cereals) are meaningless. Especially since higher vitamin intake merely means any excess is excreted.

Choosing breakfast foods that add dietary fibre is more likely to be useful, since fibre intakes are often below levels recommended for good health. And some breakfast cereals offer good value in the quantity and type of dietary fibre they contain.

Oats, for example, have particularly valuable forms of soluble fibre, and since they are unlikely to be consumed other than as breakfast porridge or muesli, these foods become worthwhile choices. Oats – and other high-fibre choices – are also satisfying, increasing feelings of fullness and reducing hunger, especially when compared with ready-to-eat cereals.

For teenage girls and many older people, calcium is another marginal nutrient. Yoghurt and cheese are good sources of this mineral, as are milk and some calcium-enriched drinks. So milk with breakfast cereals could be beneficial.

In the United States, milk on breakfast cereal contributes 28% of milk intake for those over 50 years of age and 22% to 26% of the milk consumed by younger adults. A similar proportion of milk consumed by children and teenagers is also added to breakfast cereals.

But the most common nutritional problems in developed countries are related to excesses – too many kilojoules for sedentary people and high intakes of salt, sugars and certain fats. And many popular breakfast items are unlikely to help with reducing these excesses. This includes many children’s breakfast cereals, which may be one third (or more) sugar. Pastries or banana cake (aka banana bread) are even worse because they feature sugar and other refined carbohydrates as well as saturated fat.

There may be problems in defining breakfast, but there’s ample evidence that eating a healthy breakfast has overall nutritional benefits, especially when compared with skipping breakfast.

Some of the relevant studies include this one from Australia (its author previously worked with Kellogg Australia); this one from the United States in children, and these two in adults; this one from Canada (authors supported by Kellogg Canada); this one from Belgium; this one from Korea, where benefits have been shown for the traditional breakfast of rice or noodles with side dishes featuring vegetables, eggs, meat or beans; and this one from Japan(at least for nutrients relevant to bone density studied).

Long-term health effects

More reliable longitudinal studies also show health benefits for regular breakfast eaters. The Coronary Artery Risk Development in Young Adults (CARDIA) study, for instance, checked almost 3,600 participants over an 18-year period and found breakfast eaters were less likely to be obese (especially around the abdomen), or to have metabolic syndrome, high blood pressure or type 2 diabetes.

An Australian study did a 20-year follow-up of a large group of children first surveyed when they were between nine and 15 years old and found those who skipped breakfast (defined as not eating between 6am and 9am) as children had a larger waist circumference, higher fasting insulin and higher total and LDL cholesterol levels – all risk factors for cardiovascular health – as adults.

Many studies show a higher incidence of excess weight in those who skip breakfast. Space precludes listing the many results for this aspect of breakfast, but they are well summarised (with references) in this comprehensive Finnish report that notes a relationship between regular breakfast consumption and lower Body Mass Index (BMI) in Western, Asian and Pacific regions. It also notes a few studies that have failed to find any association.

As with all studies in human nutrition and weight, there are many confounding factors. Some studies, for example, show breakfast eaters have higher levels of physical activity or spend less time watching television. The combination of skipping breakfast and late night eating, but neither on its own, may increase the risk of metabolic syndrome.

The US National Weight Control Registry reports eating breakfast is a characteristic common to successful weight-loss maintainers. Almost 80% of the 2,959 people on the register who have lost an average of 32 kilograms and kept it off for six years eat breakfast every day.

Studies show children who have eaten breakfast have better concentration, greater academic performance and more positive learning outcomes as well as fewer behavioural and emotional problems. Here’s a paper with a list of 63 references backing these claims.

As I noted at the beginning of this article, personal preferences and habits vary – and are probably very relevant here. Skipping breakfast and satisfying yourself later with junk foods will lead to poor results. But it’s possible to compensate for a missed breakfast with a nutrient-rich lunch and dinner.

For most people, it makes sense for breakfast to contribute to a healthy balanced diet without increasing intake of saturated fat, added sugars or salt. Practical choices that fit these criteria include wholegrain breads, grains or cereals (with minimal added sugar), fruit, milk, yoghurt or cheese, vegetables (perhaps tomatoes, spinach or mushrooms), and eggs, legumes, nuts or seeds.

Rosemary Stanton is a Nutritionist & Visiting Fellow at UNSW.

This opinion piece was first published in The Conversation.