Having a big breakfast and smaller dinner may not be the best way to lose weight, according to new research. A study of overweight people found they burned off a similar amount of calories regardless of when they ate the biggest meal of the day.
It suggests the old weight-loss adage ‘breakfast like a king, lunch like a prince, and dine like a pauper’ is a myth.
The idea was that front-loading calories in the morning gives our bodies more time to burn them off throughout the day.
To test the theory, researchers at Aberdeen University put 30 obese or overweight men and women on two separate diets each lasting a month.
During the first diet they had the bulk of the calories in the morning and in the second diet they had the biggest meal in the evening.
There was no difference in energy burned or weight lost between the diets. On both meal plans, participants lost 3kg (7lbs) on average.
When they had a big breakfast did, however, they reported feeling less hungry throughout the day, suggesting a big breakfast could still be a good strategy for weight watchers.
Having a big breakfast and smaller dinner may not be the best way to lose weight, according to new research
Lead author Professor Alexandra Johnstone, from the Rowett Institute at Aberdeen, said: ‘The advice to breakfast like a king is one of many myths on how to lose weight through burning calories.
‘It now appears a calorie is burned the same way regardless of the time of day.
‘However having a bigger breakfast does make people less hungry, so they could lose weight that way.’
WHAT SHOULD A BALANCED DIET LOOK LIKE?
• Eat at least 5 portions of a variety of fruit and vegetables every day. All fresh, frozen, dried and canned fruit and vegetables count
• Base meals on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain
• 30 grams of fibre a day: This is the same as eating all of the following: 5 portions of fruit and vegetables, 2 whole-wheat cereal biscuits, 2 thick slices of wholemeal bread and large baked potato with the skin on
• Have some dairy or dairy alternatives (such as soya drinks) choosing lower fat and lower sugar options
• Eat some beans, pulses, fish, eggs, meat and other proteins (including 2 portions of fish every week, one of which should be oily)
• Choose unsaturated oils and spreads and consuming in small amounts
• Drink 6-8 cups/glasses of water a day
• Adults should have less than 6g of salt and 20g of saturated fat for women or 30g for men a day
The study, published in the journal Cell Metabolism, recruited 16 men and 14 women with an average age of 50 and BMI of 32.5. A BMI of 18 to 25 is considered healthy.
Each person in the study was put on two separate diets, each lasting four weeks and containing only food and drinks provided by researchers.
During the big-breakfast diet, they got 45 per cent of their daily calories from the first meal of the day, and just 20 per cent from dinner.
While doing the big-dinner diet, they got 45 per cent of their daily calories from dinner and 20 per cent from breakfast.
On both diets, people burned just over 2,800 calories through the average day.
Therefore, they did not burn off more calories after a big breakfast, compared to a big dinner when given a fixed diet of around 1,700 calories a day.
But in the real world, where people can eat what they like after a big breakfast, the new evidence suggests breakfasting like a king could help to lose weight.
That is because people in the study felt significantly less hungry on the big-breakfast diet.
They had less of an appetite in a questionnaire asking questions on how full they felt and how much they could eat at that moment.
When breakfast was their biggest meal of the day, people also had a lower level of the ‘hunger hormone’ ghrelin and a higher level of a hormone called GLP-1, which is believed to make people feel full.
Previous studies had indicated people lose more weight when they eat more in the morning, as they may have less to eat for lunch and dinner.
The new study gave people bigger breakfasts through, for example, increasing the portion size of bacon and eggs, or adding in cereal and a smoothie.
The larger meal was found to keep people literally full up for longer, as they took an average of two hours longer to digest even half of the food eaten, based on carbon dioxide analysis of their breath.
To measure calories burned, researchers gave the study participants ‘heavy water’ to drink, and measured the balance of hydrogen and oxygen from the water in their urine afterwards.
This reveals how much carbon dioxide they have lost from their body, which is directly linked to the number of calories burned.
Professor Johnstone said: ‘There is no optimal time to eat when it comes to calories, but a big breakfast may help to control your appetite and stick to your diet when trying to lose weight.’
