Field Notes

High-Protein Diet May Slightly Increase Heart Failure Risk
in Middle-Aged Men

For middle-aged men, eating higher amounts of protein was associated with a slightly elevated risk of heart failure than those who ate less protein, according to new research from the University of Eastern Finland. Proteins from fish and eggs weren’t associated with heart failure risk in this study. The findings were reported in Circulation: Heart Failure.

Despite the popularity of high-protein diets, there’s little research about how diets high in protein may impact men’s heart failure risk.

“As many people seem to take the health benefits of high-protein diets for granted, it’s important to make clear the possible risks and benefits of these diets,” says Jyrki Virtanen, PhD, study author and an adjunct professor of nutritional epidemiology at the University of Eastern Finland in Kuopio. “Earlier studies have linked diets high in protein—especially from animal sources—with increased risks of type 2 diabetes and even death.”

Researchers studied 2,441 men, aged 42 to 60, at the study’s start and followed them for an average of 22 years. Overall, researchers found 334 cases of heart failure were diagnosed during the study, and 70% of the protein consumed was from animal sources and 27.7% from plant sources. Higher intake of protein from most dietary sources was associated with a slightly higher risk. Only proteins from fish and eggs weren’t associated with heart failure risk in this study, researchers say.

For this study, researchers divided the men into four groups based on their daily protein consumption. When they compared men who ate the most protein with those who ate the least, they found their risk of heart failure was represented by the following metrics:

• 33% higher for all sources of protein;
• 43% higher for animal protein;
• 49% higher for dairy protein; and
• 17% higher for plant protein.

“As this is one of the first studies reporting on the association between dietary protein and heart failure risk, more research is needed before we know whether moderating protein intake may be beneficial in the prevention of heart failure,” says Heli E. K. Virtanen, MSc, first author of study, a PhD student, and an early career researcher at the University of Eastern Finland in Kuopio. “Long-term interventions comparing diets with differential protein compositions and emphasizing differential protein sources would be important to reveal possible effects of protein intake on risk factors for heart failure. More research is also needed in other study populations.”

— Source: University of Eastern Finland

 

Slower Calorie Burn During Pregnancy May Cause More Retained Baby Weight in Black Mothers With Obesity

Differences in the way women with obesity burn calories during pregnancy may be a contributor to long-term postpartum weight retention in black moms, according to researchers in Baton Rouge, Louisiana. Their new study shows that despite similar levels of food intake and physical activity—and a higher proportion of fat-free mass—black women with obesity burned fewer calories than their white counterparts. The findings, which suggest a need for more individualized pregnancy weight gain recommendations for obese women, were presented at the American Physiological Society annual meeting at Experimental Biology 2018 in San Diego.

Women with obesity—defined as a BMI of 30 or above at the start of pregnancy—are at increased risk of gaining too much weight during their pregnancy and retaining weight after they give birth. In many cases, retained “baby weight” eventually becomes regular weight that may further exacerbate preexisting obesity and related health problems.

Researchers at Louisiana State University’s Pennington Biomedical Research Center and the Woman’s Hospital in Baton Rouge measured energy expenditure, body composition, and markers of metabolic health in 66 black and white pregnant women with obesity.

The women were comparable in age (average age 27), BMI (approximately 37) and body fat percentage (approximately 45%). The black women were heavier and had a higher amount of fat-free mass (muscle, bone, skin, etc), which suggests they had a higher metabolism and would burn more calories. While the black women ate roughly 300 fewer calories per day, the composition of their diet and daily energy expenditure was similar to their white counterparts. However, when the researchers compared energy expenditure—assuming that body mass was the same in black and white women—they found that black women burned roughly 230 fewer calories during the day and 80 fewer calories while sleeping.

The researchers think that the findings may be partly due to the composition of the fat-free mass in black women. Previous research has shown that while black women have a higher proportion of calorie-burning muscle, they may have a smaller liver and kidney, two organs that expend more energy than muscle. “Another hypothesis is that African Americans are more efficient in the use of energy during activity. This can be compared to a more fuel-efficient car, which consumes less gas for the same performance,” lead researcher Jasper Most, PhD, of Pennington Biomedical, explains.

Clinicians commonly recommend that pregnant women add an additional 300 to 500 kcal per day and that obese women aim to gain between 11 and 20 lbs during the course of a normal pregnancy. These findings could have implications on current nonrace-specific calorie intake recommendations for pregnant women.

“The weight gain recommendations for pregnancy are based on weight gain in relation to pregnancy outcomes such as healthy fetal size and in the absence of pregnancy complications. Therefore, our findings can’t immediately contribute to suggestions on healthy weight gain,” Most says.

“However, our findings might indeed influence the recommendations for energy intake during pregnancy. The estimated energy-intake requirements to achieve healthy weight gain are the sum of energy that a pregnant woman expends and what she stores (in fat tissue and for fetal growth, for example).

“We show that the energy expenditure is less in African American women and therefore energy intake requirements should probably be smaller for African American women. We estimate if African American women eat the amount of calories recommended for pregnant women, they would likely gain more weight in pregnancy (up to 7 kg [15 lbs] more) than what’s considered healthy,” Most says.

— Source: American Physiological Society