Does it matter when you eat

You may have heard the popular adage “breakfast like a king, lunch like a prince, dinner like a pauper”, but is it true?

Louise Deasey
December 2017

If you’re trying to lose, or maintain, weight does the time of day that you eat matter?

One of the largest human studies into the correlation between meal timing and body mass index (BMI) in humans discovered some interesting results. Researchers from Loma Linda University Adventist Health Sciences Center in California studied meal timing and frequency and the correlation with BMI in more than 50,000 people.

The results, published in The Journal of Nutrition, show that timing does, in fact, matter in weight loss. Researchers found 4 factors associated with a decrease in BMI:

• eating only 1 or 2 meals per day
• maintaining an overnight fast of up to 18 hours
• eating breakfast instead of skipping it
• making breakfast or lunch the largest meal of the day.

Regardless of overall calorie intake, participants who made breakfast the largest meal of their day lost more weight than those who ate a bigger lunch. The 2 factors associated with higher BMI were eating more than 3 meals per day (snacks were counted as extra meals) and making dinner the largest meal of the day.

The after-hours effect

Dr Kellie Bilinski, a consultant dietitian-nutritionist and spokesperson for the Dietitians Association of Australia, says animal studies have produced similar findings.

“There have been some studies where they eat the same amount at night instead of during the day (so their overall calorie intake is the same). They found the animals lost more weight and had better metabolic control (how our bodies convert the fuel we consume into energy) when they ate the same foods during the day.

“This might apply to shift workers, for example, who eat when they should be sleeping. This dietary behaviour leads to poorer metabolic control, higher insulin levels and poorer glucose control.” This can lead to weight gain and a negative health effects.

The take-away message

While eating more of your calories earlier in the day is a good general rule for healthy weight maintenance, Dr Bilinski – whose background includes a stint at the obesity clinic of the Royal Prince Alfred Hospital in Sydney – says overall intake is still the most important aspect of maintaining a healthy weight.

“A bigger breakfast is important because you’re less likely to get ravenously hungry and make the wrong decisions later in the day. [It’s] not necessarily because of the way your body processes the foods at certain times of the day.”

She says it’s important to include some lean protein with every meal and a couple of serves of carbohydrates and plenty of salad and vegetables. “Try to stay away from the mentality of restriction,” she adds. “Diets aren’t one-size-fits-all, it needs to fit with your lifestyle to be sustainable.”