Do you opt for a Diet Coke only to undo your good work by having a chocolate bar with it?
You're not alone. A new study found people who drink diet drinks may compensate for the lack of calories by eating unhealthy foods.
People who drank diet drinks ate an average of 69 calories of extra sugary, fatty, salty or cholesterol-raising foods, the study found.
Therefore, switching to diet drinks may not help people trying to control their weight to slim down if they don't pay attention to the quantity and quality of the foods they consume, the researchers concluded.
The team, led by Dr Ruopeng An, of the University of Illinois, looked at data on the dietary habits of more than 22,000 US adults.
The data covers more than 10 years and forms part of the National Health and Nutrition Examination Survey, which asked people to recall everything they ate or drank over the course of two non-consecutive days.
It included their daily calorie intakes, including their consumption of food and five types of beverages - diet or sugar-free drinks; sugar-sweetened beverages, such as sodas and fruit drinks; coffee; tea; and alcohol.
Using a database from the US Department of Agriculture, Dr An compiled a list of 661 'discretionary foods' which includes those that do not belong to the major food groups and are not required by the human body, but may add variety to a person's diet.
These energy-dense, nutrient-poor foods include items such as cookies, ice cream, chocolate, fries and pastries.
Increase in total calorie intake by beverage type:
- Alcohol: 384 calories
- Sugar-sweetened beverages: 226 calories
- Coffee: 108 calories
- Diet beverages: 69 calories
- Tea: 64 calories.
Although previous research on people's choice of drink and whether they eat discretionary foods focused on snacking in between meals, Dr An chose to look at the nutritional quality of the food participants consumed rather than when it was eaten.
Around 97 per cent of people in the study ate at least one of the five types of drinks daily.
Around 41 per cent said they drank beverages from at least two of the categories, and more than 25 per cent drank three or more types of drinks daily.
Coffee was the top beverage of choice, consumed by more than half - 53 per cent - of people in the study.
This was followed by sugar-sweetened beverages (43 per cent), tea (26 per cent), alcohol (22 per cent) and diet beverages (21 per cent).
Drinking alcohol led to the biggest increase in daily calorie intake, causing people to eat an extra 384 calories on average.
This was followed by sugar-sweetened beverages (226 calories), coffee (108 calories), diet beverages (69 calories) and tea (64 calories).
While coffee and diet-beverage drinkers ate fewer total calories each day than people who preferred alcohol or sugary drinks, a greater percentage of their daily calorie intake came from discretionary foods.
This suggests they may be a 'compensating effect' occurring, Dr An said.
When he explored associations between beverage type and the quality of a person's diet, Dr An found that people who consumed sugar-sweetened beverages or coffee had the worst nutrition profiles.
Switching to diet drinks may not help people control their weight if they don't pay attention to the quantity and quality of the foods they consume, he concluded.
If people simply substitute sugar-sweetened beverages for diet beverages, it may not have the intended effect because they may just eat more calories, rather than drinking them, Dr An said.
He added: 'We'd recommend that people carefully document their caloric intake from both beverages and discretionary foods because both of these add calories - and possibly weight - to the body.'
He also recommended that public health interventions encouraging people to assess their drinks in the context of their overall behaviour, looking at whether they eat more as a result of choosing a certain type of drink.
The research will be published in a future issue of Journal of the Academy of Nutrition and Dietetics.
