Previous studies have already suggested that mushrooms can be more satiating than meat, but this effect has never been studied with protein-matched amounts.
In this study, which was funded by the Mushroom Council, US researchers gave a group of individuals protein-matched meals of either 226 g of sliced A. bisporus mushrooms (commonly known as white button mushrooms) and 28 g of 93% lean ground beef.
According to the scientists, the participants reported less hunger and greater feelings of fullness after the mushroom breakfast. They also planned to eat less in the subsequent meal (‘decreased prospective consumption’).
"As with previous published research, this study indicates there may be both a nutritional and satiating benefit to either substituting mushrooms for meat in some meals or replacing some of the meat with mushrooms," said study author and professor at the University of Minnesota Joanne Slavin.
Not all proteins are equal
Protein quality is determined by its protein digestibility corrected amino acid score (PDCAAS).
According to a 1989 FAO and WHO expert consultation, the highest quality protein sources in this index are animal proteins, such as milk and eggs, which both have a PDCAAS value of 1.00).
Cooked lentils and mushrooms have a PDCAAS value of 0.66, while wheat protein sits at 0.42.
Other factors at play?
The researchers admit that the mushroom and meat-based breakfast meals were matched for protein content but not for fibre, carbohydrate, fat, energy content or total weight.
Mushrooms contain several different types of non-digestible carbohydrates such as chitin, β-glucans, raffinose, oligosaccharides and resistant starch.
“The differences in portion size and fibre content between the two sandwiches may explain the greater satiating effect of the mushroom sandwich. The strongest predictor for satiety may be portion size, especially for overweight and obese individuals, who need to consume greater volumes of food to feel satiated.”
The greater volume of mushrooms would likely take more time and effort to chew, which could promote a feeling of fullness. Chewing promotes saliva and gastric acid secretion, both of which may increase gastric distention and promote a feeling of fullness.
Fibre content, which also contributes to food volume, may have contributed to the greater satiating effect of the mushroom breakfast, however “our results do not suggest evidence for a uniquely satiating effect with mushroom fibres”, write the authors.
Nutrition research coordinator at the Mushroom Council Mary Jo Feeney said: "Consumers are interested in the benefits of protein food choices, so it's important for them to know that plant-based sources of protein, such as mushrooms, can be satisfying."
The intervention was designed as a randomised, open-label, crossover study, with 32 participants (17 women and 15 men) who were given two servings of mushrooms or meat for 10 days, for breakfast and dinner.
Individuals in the mushroom group avoided eating beef during the study, and vice versa for those in the meat group.
After the first breakfast, participants rated their satiety using visual analogue scales (VAS) at the baseline and then at regular intervals after the meal. Three hours later, participants ate an ad libitum lunch.
For the following nine days of the study, individuals prepared and ate the meat or mushrooms at home for breakfast and dinner, and kept ‘hunger diaries’ on day one, two and 10.
In addition to measuring the impact on satiety and hunger, the researchers also noted no significant differences in participant ratings of satisfaction, nor were there statistically significant differences in energy intake at the ad lib lunch or according to the diet diaries on day one, two or 10.
Source: Appetite Journal
“Impact of Agaricus bisporus mushroom consumption on satiety and food intake”
Available online ahead of print, doi.org/10.1016/j.appet.2017.06.021
Authors: Julie M. Hess, Qi Wang, Clarissa Kraft, Joanne L. Slavin