Research suggests that we can no longer blame delicious foods for our weight gain.
Most of us have heard the saying that "if it tastes good, it must be bad for you." Although commonly held, this old adage may not contain much truth after all.
A team of researchers led by Dr. Michael Tordoff, a physiological psychologist at Monell Chemical Senses Center in Pennsylvania, set out to test this belief in more detail. "Most people think that good-tasting food causes obesity," he explains.
Tordoff was unconvinced, and he therefore designed a range of experiments to see whether the theory held any water. His findings were recently published in the journal Physiology & Behavior.
Investigating flavor and weight gain
Previous studies that have drawn conclusions about good taste (in this context, meaning flavor and texture) and its effect on weight gain have been flawed. For instance, many did not take into account the impact of variety on feeding behavior; having a spread of different foods to choose from can cause one to over-indulge. A buffet is a prime example of this.
According to the authors of the recent research, only three studies to date have looked specifically at the influence of flavor on weight gain. None of these studies were conclusive, however. The reasons for this include sample size and, once again, the effects of variety.
The first phase of Tordoff's study involved establishing whether mice would prefer food with added oily or sweet ingredients that were non-nutritive. The mice were served two pots of chow - one standard, and one with either a sucralose sweetener or mineral oil (both of which are calorie free).
As expected, the mice preferred the mineral oil chow and sucralose chow. They virtually ignored the plainer fare. In fact, the mice thought so little of the standard chow that, according to the study authors, they "often defecated in the cup containing the plain diet."
Does tasty food encourage overeating?
The second phase of the trial involved splitting the mice into three groups, with each being fed a different diet for 6 weeks: plain chow, chow with mineral oil, or chow with sucralose.
At the end of the 6-week period, the mice were measured. There were no significant differences in weight or fat content in any of the three experimental groups. In other words, even the more tasty foods did not encourage overeating.
"Even though we gave mice delicious diets over a prolonged period, they did not gain excess weight. People say that 'if a food is good-tasting it must be bad for you,' but our findings suggest this is not the case. It should be possible to create foods that are both healthy and good-tasting."
Dr. Michael Tordoff
After the 6-week diet, the mice were still found to preferentially eat the tastier chow when offered standard chow, demonstrating that they had not tired of the enhanced food.
In a third arm of the research, the team fed the mice a high-fat diet that is known to contribute to obesity in mice. The researchers added sucralose to this food to make it even more delicious. They found, however, that the time taken for the mice to become obese was no different; the increase in pleasant taste did not influence the amount of food eaten. In fact, sucralose slightly reduced weight gain and fat stores.
The conclusion drawn is that good-tasting food alone does not influence obesity. Flavor determines what we choose to eat, but not how much of it we eat over the longer term.