Pulls from HEALTH BENEFITS AND RISK ASSOCIATED WITH ADOPTING A VEGETARIAN DIET by Wiesław Pilis, Krzysztof Stec1, Michał Zych, Anna Pilis
The potential effectiveness of vegetarian diets for dealing with obesity was observed in a study by Ton- stad et al.  conducted on a group of 22,434 men and 38,469 women where BMI was measured in six treatment groups (vegetarians, vegans, lacto-ovo-vege- tarians, semi-vegetarians, fish eaters, and meat eaters). The mean BMI was found lowest in the vegans (23.06 kg/m2) and gradually increased as follows, lacto-ovo- -vegetarians (25.7 kg/m2), fish eaters (26.3 kg/m2), semi- -vegetarians (27.3 kg/m2) and meat eaters (28.8 kg/m2, p<0.001).
Vegans also showed significant differences to meat eaters (i.e. controls) by having lower blood levels of leukocytes (p<0.05), neutrocytes (statistically insignificant), platelets (p<0.05) and urea (p<0.05) but a higher concentration of albumin (p<0.05). These values may indicate a lower content of protein in the vegetarian diet. In addition, vegetarians run the risk of having a deficiency of iron, calcium, zinc, vitamin D, and B12, as well as of amino acids.
Eating large amounts of vegetables and fruits, which form a major part of all vegetarian diet types, also has a beneficial effect on the cardiovascular system. Plant based foodstuffs (e.g. apples, onions, broccoli, berries, olives, lettuce, tomato, red pepper, grapefruit etc.) provi- de the body with multiple antioxidants. The most active of these include the antioxidant vitamins (α-tocopherol, ascorbic acid), flavonoids and carotenoids (lycopene, lutein, β-carotene, cryptoxanthin, zeaxanthin). Their biological activity are based on inhibiting the oxidation of LDL cholesterol, increasing HDL cholesterol and re-ducing total cholesterol concentrations in the circulation.
A study by Somannavar and Kodliwadmath  confirms that vegetarians have significantly higher antioxidant levels compared to those eating a mixed diet (p<0.001). Another health benefit for adopting a vegetarian diet is that blood levels of total cholesterol (T-C) and LDL cholesterol (LDL-C) are maintained correctly. The plasma lipid profiles of vegetarians and those eating a traditional diet was studied by Dourado et al  which demonstrated that the latter group had significantly higher average T-C (207.11 mg/dl) and LDL-C (143.79 mg/dl) blood concentrations compared to the former at respectively T-C; 160.06 mg/dl, LDL-C; 87.40 mg/dl (p<0.001). Both of the last aforementioned studies also show that meat eaters have a significantly higher systolic blood pressure (123.76 mmHg) compa- red to vegetarians (114.86 mmHg) (p<0.05).
The authors take the view that the high amounts of carbohydrates and low amounts of fat as seen in vegetarian diets increases cellular insulin sensitivity thereby affording some protection against diabetes. This hypothesis was checked in a study by Tonstad et al  conducted on a group of 38,469 women and 22,434 men. It was found that the incidence of type 2 diabetes occurred in the following groups in descending order of magnitude; meat eaters (7.6%), semi-vegetarians (6.1%), fish eaters (4.8%), lacto-ovo-vegetarians (3.2 %) and vegans (2.9%), (p<0.05).
As reported by Borrine et al , the body’s need for protein is associated with being provided with adequate amounts of carbohydrates. The body consumes up to twice as much protein du- ring intense exertion when insufficiently supplied with carbohydrates. A high carbohydrate intake beneficially affects muscles and regulates the level of glycogen. … Barr et al.  confirmed that the high proportion of carbohydrates in the diet is associated with obtaining better results for endurance sports.
Based on research conducted by the American Dietetic Association and Dieticians of Canada , iron intake successively increases for each of the following groups; vegans, lacto-ovo-vegetarians and meat eaters. … A loss of iron in athletes is demonstrated by gastrointestinal bleeding, increased sweating, haemo- lysis and menstrual disorders in women. In most cases, vegetarian athletes can adjust the level of iron by eating foods rich in vitamin C, citric acid, malic acid, tartaric acid, fructose and sorbitol.
Burke et al.  have stated that the administering creatinine as a dietary supplement can significantly (p<0.05) increase the physical per- formance and muscle strength of athletes that follow a vegetarian diet.