The avocado’s effectiveness in reaching feelings of fullness and what is known as the Satiety Index may be a key link to effective weight loss. The Internet is buzzing with the latest research released in Nutrition Journal’s November 2013 publication, which found that consuming half an avocado leads to a reduced chance of snacking after meals and a greater feeling of fullness.
The answer, while seemingly simple, lies in large part in people’s feelings of satiety. "People who feel satisfied are less likely to snack between meals," said Dr. Joan Sabate, Chair of the nutrition department of Loma Linda University.
The trial
For the study, 26 people ages 25 to 65 who were overweight and moderately obese (with a body mass index higher than 25 but less than 35) were given the same breakfast for three days. Then for lunch, the participants ate one of three meals: a control lunch, which did not include avocados but had a salad, a French baguette and some chocolate chip cookies; an avocado-inclusive lunch, which included about half an avocado (but where portion sizes of salad dressing and cookie were reduced so that the calories and nutrients were still the same as the control lunch); and an avocado-added lunch, which included about half an avocado in addition to the control lunch.
The results
Researchers found that participants who added half a fresh avocado to their lunch reported 40% decreased desire to eat in the following three hours as well as a 28% reduced desire to eat over the subsequent five hours. In addition, they reported increased feelings of satisfaction over the three hours following the meal.
However, the researchers did note that addition of the half-avocado did mean an additional consumption of 112 calories. Avocados are known to be high in fat -- but they're high in the good kinds of fats, called monounsaturated fat, that are known to help lower cholesterol levels.
Study leader, Dr Joan Sabate, said: "Satiety is an important factor in weight management, because people who feel satisfied are less likely to snack between meals. We noted that though adding avocados increased participants' calorie and carbohydrate intake at lunch, there was no increase in blood sugar levels beyond what was observed after eating the standard lunch. This leads us to believe that avocados’ potential role in blood sugar management is worth further investigation".
Satiety – or the feelings of fullness – provides a regulatory signal to our brains when it’s time to stop eating. This is done through our bodies as food and drink is consumed, digested and absorbed. So if our bodies would just listen to when our feelings of fullness arrived, wouldn’t we have already solved our own weight issues and curbed our eating habits long ago?
Unfortunately, it’s a more complex story than that, as full satiety signals often take 15-20 minutes after eating before people process the complete feeling of fullness. The British Nutrition Foundation reveals there are a number of other factors that also control our eating behavior and impact satiety – including portion size, emotional states and social situations which may or may not include alcohol.
The Satiety Index
The avocado’s key ability to lead to feelings of fullness and impact weight loss is not lost amongst other foods which also curb hunger through the Satiety Index.
A quick scan of the Satiety Index reveals that in general, fruits (such as oranges, bananas, apples) and proteins (lentils, cheese, fish and beef) rank quite high on the index scale. Some carbohydrates do as well; potatoes rank at 323%, for example. The list of foods low on the index include snacks, such as peanuts, chips and ice cream.
Best choices
Some of the best foods for satiety include proteins such as eggs, beans and the aforementioned beef. And for a snack that did make the Satiety Index score: popcorn. As long as it’s not “smothered in butter, oil, and salt,” the hull is rich with polyphenols – antioxidants with disease-fighting properties. And of course, the avocado, with its ability to aid in the feelings of fullness is amongst the other foods to help the journey of effective weight loss.
Sources: http://www.medicalnewstoday.com/ , http://www.dailymail.co.uk/, http://www.huffingtonpost.com/, http://guardianlv.com/