Scientific Update

Meat Is Associated With Weight Gain

A new study suggests that eating meat is associated with weight gain. This study looked at how more than 350,000 people ate and how their weight changed over approximately five years. For this study's purposes, 'meat' included red meat (beef, veal, pork, lamb), processed meat, and poultry but not fish. In this very large study, eating approximately 8 ounces of meat a day led to a greater weight gain, close to a pound a year, compared to the weight gain seen in someone eating less meat but the same amount of calories. Over a five-year period, this difference would result in approximately 4.5 pounds of weight gained. Weight gain can lead to obesity and increased risk of many chronic diseases. The results of this study suggest that reducing (or eliminating) both red meat and poultry is one action that non-vegetarians can take to keep from gaining weight as they get older. The study's authors recommend that people decrease their meat consumption to improve their health.

Vergnaud A-C, Norat T, Romaguera D, et al. 2010. Meat consumption and prospective weight change in participants of the EPIC-PANACEA study. Am J Clin Nutr 92:398-407.

Vegan Meals Popular in School Lunch Program

School meals are not typically vegan-friendly, and all too often, they are also too high in fat and saturated fat. Researchers with the Physicians' Committee for Responsible Medicine (PCRM) thought that adding vegan items to a school menu would result in healthier lunches but wondered if students would accept these items. They conducted a study in an elementary school and a middle school, both in Florida. Forty percent of the schools' students received free and reduced-price lunches. A vegan item, along with non-vegan options, was offered in each cafeteria once a week for one month. Vegan items were a veggie burger, vegetarian chili, and rice and beans. These items were lower in fat and saturated fat and higher in fiber than the non-vegan items.

The day before the menu item was served, students had a taste test and received rewards for trying samples. The students enthusiastically accepted the vegan items, with sales of 76 percent of total items sold in the elementary school and 56 percent in the middle school being the vegan items. This study suggests that students are willing to purchase vegan options and that their inclusion can result in healthier choices in a school lunch program. If students are familiar with these foods, they may be more likely to incorporate them into their daily diet and may even ask their family to prepare foods like these. We hope this program can be expanded and adopted by other school districts.

Eckart J, Strong K, Niooert DK, et al. 2010. Students' willingness to purchase vegan menu items in the National School Lunch Program. Florida Public Health Rev 7:64-69.

What Influences People to Make Major Dietary Changes?

Scientific research shows that moving to a plant-based diet has significant health benefits, but there have been almost no studies about the best ways to encourage people to make dietary changes. Research into human behavior suggests that there are several stages of change. The first stage, precontemplation, is when an individual is not aware of any need to change his or her behavior. For instance, he or she never really thought about following a plant-based diet. The next stage, contemplation, is when a person begins to acknowledge that a change would be helpful but hasn't taken any action yet. This is followed by the action stage and then by the maintenance stage. If lasting behavior change is to happen, people must move from the precontemplation stage through to the maintenance stage. Attitudes about a plant-based diet can influence behavior, as can perceptions about whether an individual thinks he or she can make a dietary change. The expected reaction of significant others (friends, family, co-workers) also plays a role in determining whether behaviors will change.

Researchers studied more than 200 college students at a large university in the northeastern United States. Participants were categorized by their stage of change with regard to plant-based diets. Females were significantly more positive about plant-based diets than males and were more likely to report that they intended to adopt a plant-based diet. As expected, the farther along the stages of change the participants were, the more likely they were to be positive about a plant-based diet and about their intent to change to this diet. People identified as being in the contemplation stage were more likely to report that their significant others would react positively towards their dietary change than were people in the precontemplation stage.

Both males and females said that improved health was the main advantage of adopting a plant-based diet; both groups were concerned about protein adequacy. Females were motivated to reduce the harm to animals; males did not list this as an advantage. Males were more concerned with the taste of food and with possible muscle loss; females were more concerned about having a variety of foods to eat and missing foods they currently eat. Concerns were also expressed about the availability and affordability of food and of support from others.

These results give us some ideas to encourage people to make important dietary changes. At least for college students, messages that promote improved health and information about plant-based protein appear to be important. Males seem to want to know how to maintain strength and body size; women are more interested in nutritional benefits and familiar foods. The results of studies like this one can help vegetarian organizations be more effective in promoting dietary change.

Wyker BA, Davison KK. 2010. Behavioral change theories can inform the prediction of young adults' adoption of a plant-based diet. J Nutr Educ Behav 42:168-77.

Vitamin B12 in British Vegetarians

A recently published study from the United Kingdom reminds us that having a reliable source of vitamin B12 is important in a healthy diet. We should note that this study was conducted close to 10 years ago, so the results that follow may not reflect vitamin B12 statuses of vegetarians and vegans in the UK today.

In this study, close to 700 men were surveyed (onethird vegan, one-third vegetarian [mainly lacto-ovo], and one-third non-vegetarian). More than half of the vegans, 7 percent of vegetarians, and one non-vegetarian were classified as vitamin B12-deficient based on blood vitamin B12 levels. An additional 21 percent of vegans, 17 percent of vegetarians, and 1 percent of non-vegetarians had blood vitamin B12 levels that were very low, though not categorized as deficient. Despite the fact that 20 percent of vegans and vegetarians reported taking a vitamin B12 supplement regularly, the researchers found that blood levels of vitamin B12 were not higher, on average, in men using supplements. This may be because the subjects reported inaccurately, their supplements did not contain true vitamin B12, or some men had recently started taking a supplement and it had not had time to take effect.

As Vegetarian Journal readers know, vegans must eat foods fortified with vitamin B12 or use a vitamin B12 supplement to avoid deficiency. For more information about vitamin B12, see and

Gilsing AMJ, Crowe FL, Lloyd-Wright Z, et al. 2010. Serum concentrations of vitamin B12 and folate in British male omnivores, vegetarians, and vegans: results from a cross-sectional analysis of the EPICOxford cohort study. Eur J Clin Nutr [Epub ahead of print].

Vegetarians in Belgium

A small study in Belgium compared 106 vegetarians with 106 non-vegetarians. The main difference between the groups was diet; they were matched by sex, age, Body Mass Index (BMI), physical activity, tobacco use, and alcohol consumption. In most cases, vegetarians had dietary intakes that were closer to recommendations than non-vegetarians. Vegetarians had lower total and saturated fat intakes, and vegetarian men had lower sodium intakes. Fruits and vegetables, iron, zinc, and fiber were higher in vegetarians' diets, while vegetarian women also had higher intakes of calcium, potassium, and magnesium than non-vegetarian women. The researchers suggest, "The vegetarian diet consumed in this group is adequate to sustain the nutritional demands in a better way than the omnivorous diet," and recommend that use of a vegetarian diet could lead to an improvement of the Belgian food pattern and ultimately to a reduction in chronic disease.

Deriemaeker P, Alewaeters K, Hebbelinck M, et al. 2010. Nutritional status of Flemish vegetarians compared with non-vegetarians: a matched samples study. Nutrients 2:770-80.