Eating patterns: how do they affect our health?

October 24, 2017

Everywhere we turn, be it health magazines, diet books or social media posts from “health and fitness warriors”, we are confronted with nutrition advice to promote weight loss. For instance, the advice to have frequent small meals throughout the day to control hunger while increasing metabolism has been repeated so often that many have come to believe it.

Breakfast is often described as the most important meal of the day, yet we are also told that intermittent fasting or skipping meals is the way to better health. Or perhaps it’s eating carbs after 6 PM that is the real cause of our weight gain woes? With the abundance of often contradictory nutrition information out there, it’s no wonder that people are confused. So, do different eating patterns, such as when and how often we have meals and snacks, really affect our waistlines, or is overall energy intake and the healthfulness of the diet more important?

As a School of Exercise and Nutrition Science PhD student, I aimed to answer some of these questions during my PhD, and will offer a brief introduction to this topic.

Eating frequency and weight loss

Earlier observational studies had reported that an increase in eating frequency was linked to a lower likelihood of being overweight, but correlation does not indicate causation. In fact, recent studies, that take people underestimating their energy intakes into account, have found different results. This raises the possibility that increased eating frequency may instead promote weight gain, in line with research that shows a positive association between eating frequency and total energy intake.

Utilising data on adults from the most recent Australian Health Survey, my PhD research was designed to address the issue of energy intake misreporting. Although I had identified a positive link between eating frequency and being overweight when meals and snacks occasions were examined separately, the positive relationship was only found for snack frequency. This finding was no surprise, given that my research also found that meal frequency, but not snack frequency was associated with better adherence to national recommendations for healthy eating in both men and women.

Eating patterns are complex

How often we eat may only be one important aspect for health. Emerging research also suggests that the timing of meals and snacks may play an important role in body composition and cardiovascular health. The link between timing of eating and health may be explained by our inbuilt “body clocks”, otherwise known as circadian rhythms. Circadian rhythms govern many physiological processes, including how we respond to food at different times of the day.  Indeed, studies in mice have found that eating during their normal sleep time has a negative health impact, but few studies in humans have been designed to study the health effects of eating patterns across the day.

During my PhD, I applied a data-driven statistical technique to find distinct daily patterns of meal timing and frequency in Australian adults. My research found evidence of a “Grazing” style eating pattern, characterised by higher snack frequency and energy intake from snacks and eating later in the day (i.e. after 8pm).  This pattern was also associated with higher intakes of discretionary (i.e. junk) foods in both men and women.  Women who were overweight or obese were also more likely to have a “Grazing” pattern, after taking in to account energy misreporting.

So, what are the implications of this research for dietary messages about eating patterns, and particularly, snacking behaviours?

My PhD research, along with other research, highlights two key healthy eating messages:

• Regular meals are important to promote healthy eating.
• Improving the quality of food choices consumed as snacks may be an important intervention strategy for improving diet quality and preventing weight gain.

Ms Rebecca Leech

My PhD research was conducted within the Institute for Physical Activity and Nutrition (IPAN), under the supervision of Associate Professor Sarah McNaughton, Professor Anna Timperio and Professor Tony Worsley.