In a small study, Spanish researchers randomly assigned 20 obese men to either a Mediterranean diet, or a low fat, high complex carbohydrate diet (with foods like pasta and cereals) for a year. After a year on their respective diets, both groups saw increases in various gut microbes that are thought to be protective against type 2 diabetes (Roseburia and Parabacteroides  distasonis for Med diet, and Prevotella and Faecalibacterium prausnitzii for low fat, high complex carb diet). The Mediterranean diet group also increased their insulin sensitivity over the year, meaning that their bodies better respond to insulin.
The Journal of Clinical Endocrinology and Metabolism. 2016 Jan;101(1):233-42. (Haro C et al.)

To see how diet during pregnancy affects the risk of childhood obesity, researchers analyzed data from over 1,800 mother-child pairs. They found that children were less likely to have a high waist circumference (a measure of abdominal obesity) at age 4 if their mothers were most closely following a Mediterranean diet during pregnancy. However, the researchers found no significant relationship between the expectant mothers’ diet and the subsequent BMI of their children in early childhood.
Pediatric Obesity. 2016 Jan 13. (Fernandez-Barres S) [Epub ahead of print]

Healthy food choices can be an important way to help prevent gestational diabetes, a type of diabetes that occurs during pregnancy. To learn more about types of foods that might be helpful or harmful, Harvard researchers analyzed the diets and health outcomes of over 15,000 women. They found that replacing two servings per week of potatoes with whole grains lowered the risk of gestational diabetes by 12% (compared to 10% for replacing potatoes with legumes, and 9% for replacing potatoes with other vegetables).
British Medical Journal. 2016 Jan 12;h6898. (Bao W et al.)

While most nutrition studies focus on food and nutrients, traditions and culture can also be used to enrich wellness. To see how changing the menu at nursing homes to reflect more culturally tailored meals affects dementia patients, Norwegian researchers conducted in-depth interviews with family members and nurses of patients at six nursing homes, spanning three cultural groups: Sami (or Lapps), Norwegian, and Black South African. According to the researchers, “Familiar tastes and smells awoke pleasant memories in patients and boosted their sense of well-being, identity and belonging, even producing words in those who usually did not speak.” They concluded that “traditional food further improves patients’ appetite, nutritional intake and quality of life.”
Journal of Clinical Nursing. 2016 Jan 11. [Epub ahead of print] (Hanssen I et al.)

Obesity prevalence among U.S. immigrant children, particularly those from Mexico, is high, so researchers are trying to understand how diet plays a role. Pennsylvania researchers analyzed the diet quality of Mexican immigrant mothers and their children across multiple generations. They found that first generation American children were more likely to abandon their traditional Mexican diet for more American foods (like fast food and highly processed foods), significantly lowering the nutritional quality of their diet. This suggests that encouraging families to cook with traditional ingredients, and encouraging retailers and farms to offer these traditional ingredients, may be a good strategy to improve the health of immigrant populations.
Social Science & Medicine. 2015 Dec 21;150:212-220. (Dondero M et al.)

Researchers in Seattle created a Mexican Diet Score to assess how traditional Mexican diets are related to insulin resistance and inflammation. Higher Mexican Diet Scores indicate eating more traditional Mexican foods, such as corn tortillas, beans, soup, fruits, vegetables, whole grains, and Mexican cheese, and lower levels of added sugars, refined grains, and added fats. In a study of nearly 500 healthy, post-menopausal women of Mexican descent, the researchers found that those most closely following a traditional Mexican diet had 23% lower levels of hsCRP (a measure of inflammation), and 15% lower insulin levels (indicating healthy blood sugar regulation) than those not following a traditional Mexican diet. In the overweight and obese women, a low Mexican diet score was also linked with higher insulin resistance. The researchers concluded that “greater adherence to traditional Mexican diets… could be beneficial in reducing the risk of obesity-related systemic inflammation and insulin resistance for women of Mexican descent.”
The Journal of Nutrition. 2015 Dec;145(12):2732-40. (Santiago-Torres M et al.)

Whole grains are a classic centerpiece to the morning meal for many families, but students may especially benefit from this practice. Researchers collected data from nearly 700 elementary school students in Kansas (average age = 7.5) to see how eating breakfast relates to standardized test scores. They found that while breakfast eaters scored significantly higher in all test areas, what the students ate made a big difference. Greater servings of whole grains were significantly related to higher scores in reading comprehension and fluency and math, while fruit juice was significantly correlated with lower math and reading comprehension and fluency scores.  
Journal of the American College of Nutrition. 2015 Dec 23:1-8 [Epub ahead of print] (Ptomey LT et al.)

A common belief among athletes is that going gluten-free might help performance. To investigate this popular belief, Australian scientists randomly assigned 13 competitive cyclists without celiac disease to a 7 day gluten containing diet or a 7 day gluten free diet. The cyclists then went through a 10 day washout period, before trying the other diet, serving as their own controls. There was no significant difference in time trial performance of the athletes on either diet, nor were there significant differences in markers of inflammation or intestinal injury.
Medicine and Science in Sports and Exercise. 2015 Dec;47(12):2563-70.

Cooking vegetables in olive oil is a hallmark of the much-praised Mediterranean diet. To see how different cooking methods affect the antioxidant capacity of vegetables, Mexican researchers compared the antioxidant capacity in potatoes, tomatoes, eggplant, and pumpkin that were raw, deep fried in olive oil, sautéed in olive oil, or boiled. They found that the veggies deep fried in olive oil had the greatest total phenols, followed by the sautéed veggies, then the boiled veggies. The researchers suggest that “deep frying and sautéing conserve and enrich the phenolic composition.” That said, there is no “bad” way to eat vegetables. Rather, this research shows that if it takes a bit of olive oil to make vegetables most delicious to you, all the better.
Food Chemistry. 2015 Dec 1;188-430-8. (Ramirez-Anaya Jdel P et al).

There is more to healthy eating than just salads — whole grain pasta could be a great pick for dieters looking to curb hunger. In a small study, 8 healthy adults were assigned to a lunch of either a refined grain pasta, a refined grain pasta with lemon juice, a refined grain pasta with legumes, or a whole grain pasta – all with the same amount of calories. Each week, the participants were assigned to a different pasta meal, serving as their own controls. The researchers found that the whole grain pasta “resulted in significantly greater fullness and reduced hunger and prospective [later] food intake.” The scientists also found that whole grain pasta was just as popular among the participants as the other meals, noting that “palatability ratings did not differ.”
Applied Physiology, Nutrition, and Metabolism. 2015 Nov 16:1-7. (Cioffi I et al.)

Macular degeneration, an eye condition that can lead to blindness, has no cure or restorative treatment, so prevention is especially important. To study how diet is related to this condition, scientists analyzed the eating patterns of over 2,500 adults, then monitored their eye health for thirteen years. They found that those most closely following the Mediterranean diet (especially those people eating lots of fish and vegetables) were 26% less likely to progress to advanced age-related macular degeneration. Results varied by genetics, with certain gene carriers being more responsive to diet than others.
American Journal of Clinical Nutrition. 2015 Nov;102(5):1196-206. (Merle BM et al.)