LOW FAT VERSUS LOW CARB: BOTH WORK FOR WEIGHT LOSS
NEWSBREAKS INCLUDE:
[black small square] Childhood Obesity
[black small square] Energy Drinks
The question of which diet is best for which people has led to some strange prescriptions. However, reputable researchers are looking for a means of telling who might do better on 1 type of diet rather than another. In a new study, researchers investigated whether having information about a person's DNA makeup and/or insulin secretion levels might inform the choice about what type of diet to choose.
Previous research has suggested that a person's insulin levels or certain genes could interact with different types of diets to influence weight loss.
The researchers examined this idea with 600 overweight adults who underwent genetic and insulin testing before being randomly assigned to reduce fat or carbohydrate intake. Those who were included in the trial were considered to be overweight or obese at entry. Exclusion criteria included having diabetes, uncontrolled hypertension or metabolic disease, cancer, and diseases of the heart, kidney, or liver. After randomization into either a low-fat or low-carbohydrate dietary intervention, participants received 22 sessions over a 12-month period, led by registered dietitian health educators.
The participants were initially instructed to reduce their total fat or carbohydrate intake to 20 g/d during the first 8 weeks of intervention and then slowly added back either fat or carbs into their diet, not surpassing the lowest level of sustainable intake each participant could individually maintain.
Gene analyses identified variations linked with how the body processes fats or carbohydrates, which the researchers thought would make them more likely to lose weight on a low-fat or low-carb diet. The results showed no significant interaction between the amount of weight loss, individual genotype responsiveness patterns-a low-fat or low-carb-responsive genotype-and appropriate matching to corresponding diet type ([latin sharp s] = 1.38, -0.72 to 3.49, P = .20).
However, weight loss averaged approximately 13 lb over a year, regardless of genes, insulin levels, or diet type. In addition, some people lost as much as 60 lb, and others gained 15 lb-more evidence that genetic characteristics and diet type appeared to make no difference. According to the DIETFITS (Diet Intervention Examining The Factors Interacting with Treatment Success) trial, weight loss after 12 months was similar between the diet types, with an average weight loss of 11.68 lb for the healthy low-fat diet and 12.23 lb for the healthy low-carbohydrate group (mean between-group difference, 1.54 lb; 95% confidence interval, -0.44 to 3.53 lb). Similarly, there was also no interaction between the extent of weight loss after a year with diet-insulin secretion (INS-30) ([latin sharp s] = 0.08, -0.13 to 0.28, P = .47).
What seemed to make a difference was healthful eating. Researchers claimed that it was participants on both diets who consumed the fewest processed foods, sugary drinks, and unhealthy fats and ate the most vegetables lost the most weight. The results suggest that "precision medicine is not as important as eating mindfully, getting rid of packaged, processed food and avoiding unhealthy habits like eating while watching television."
Source: Gardner C, Trepanowski JF, Del Gobbo LC, et al. Effect of low-fat vs low-carbohydrate diet on 12-month weight loss in overweight adults and the association with genotype pattern or insulin secretion: The DIETFITS randomized clinical trial. JAMA. 2018. DOI: 10.1001/jama.2018.0245.
HIGH-PROTEIN DIETS NOT LINKED TO PREDIABETIC RENAL COMPLICATIONS
For many older people, eating a higher-protein diet may be 1 way to control weight and enhance physical function, but concerns regarding adverse renal effects of a high-protein diet (ie, a protein content of >25% of energy consumed or more than 2 g of protein per kilogram of body weight) remain. Individuals with obesity-related conditions, such as metabolic syndrome, prediabetes, and Type 2 Diabetes, are potentially more susceptible to hypertension than their healthy counterparts. Specifically, concerns about detrimental renal effects of a high protein intake have been raised because of an induced glomerular hyperfiltration, because this may accelerate the progression of kidney disease. The aim of the new substudy was to assess the effect of a higher intake of protein on kidney function in prediabetic men and women, 55 years and older. Analyses were based on baseline and 1-year data in a subgroup of 310 participants included in the PREVIEW project (PREVention of diabetes through lifestyle Intervention and population studies in Europe and around the World). Protein intake was estimated from 4-day dietary records and 24-hour urinary urea excretion. The study used linear regression to assess the association between protein intake after 1 year of intervention and kidney function markers: creatinine clearance or estimated glomerular filtration rate, urinary albumin-creatinine ratio, urinary urea-creatinine ratio, serum creatinine, and serum urea before and after adjustments for potential confounders. A higher protein intake was associated with a significant increase in urea-creatinine ratio (P = .03) and serum urea (P = .05) after 1 year. There were no associations between increased protein intake and creatinine clearance, estimated glomerular filtration rate, albumin-creatinine ratio, or serum creatinine. The researchers conclude that their study found no indication of impaired kidney function after 1 year with a higher protein intake in prediabetic older adults.
Source: Nutrients 2018, 10, 54; doi:10.3390/nu10010054.
DO NEWEST DATA SHOW CHILD OBESITY CONTINUES TO INCREASE?
Despite reports in recent years suggesting that childhood obesity could be reaching a plateau in some groups, the big picture on obesity rates for children aged 2 to 19 years remains unfavorable. Three decades of rising childhood obesity continued their upward trend in 2016, according to a new analysis. The findings show that 35.1% of children in the United States were overweight in 2016, a 4.7% increase compared with that in 2014.
According to researchers approximately 4 years ago, there was evidence of a decline in obesity in preschoolers. They caution that any decline that may have been detected by looking at different snapshots in time or different data sets has reversed course. The long-term trend is clearly that obesity in children of all ages is increasing. The data are based on body mass index (BMI) data for 3340 children participating in the National Health and Nutritional Examination Survey (NHANES) in 2015 to 2016, a large database updated every 2 years. Researchers examined data back to 1999 that include 33 543 children.
The researchers identified notable spikes between 2014 and 2016 in obesity for preschool boys, which rose from 8.5% to 14.2%, and girls aged 16 to 19 years, whose rates of obesity jumped from 35.6% to 47.9%.
Boys and girls aged 16 to 19 years had the highest rates of any age group in 2016, with 41.5% considered overweight, defined by the Centers for Disease Control and Prevention as having a BMI at or greater than the 85th percentile for age and sex. Among these 16- to-19-year-olds, 4.5% have class III obesity, the highest of 3 categories defined by the Centers for Disease Control and Prevention.
Both classes II and III are considered severe and are linked with a greater risk of heart and metabolic health problems, such as high blood pressure and cholesterol.
Across all age groups, African American and Hispanic children had higher rates of overweight and all levels of obesity, whereas Asian-American children had markedly lower rates. The most prominent trend since 1999 is the increase in all levels of overweight for Hispanic girls and overweight and class II obesity (BMI that is at least 120% greater than the 95th percentile for age and sex) among Hispanic boys. Study limitations include relying on 2-year data that provide snapshots in time across a wide population. While the NHANES database is a broader data source than sources for studies that have found declines in obesity rates among smaller or segmented populations, the NHANES 2015 to 2016 data are also the first to include enough data to create a nationally representative sample in Asian-American children, the race or ethnic group in whom rates were actually lowest, at 23.2%. Although the latest trends show that we have not figured out what works as a population, we do know that individual changes can support families' health.
Source: Duke University Medical Center. Newest data shows childhood obesity continues to increase: Across all ages, African-American, Hispanic children have highest rates, February 26, 2018. ScienceDaily. http://www.sciencedaily.com/releases/2018/02/180226122537. Accessed March 21, 2018. Journal Reference: Asheley Cockrell Skinner, Sophie N. Ravanbakht, Joseph A. Skelton, Eliana M. Perrin, Sarah C. Armstrong. Prevalence of Obesity and Severe Obesity in US Children, 1999-2016. Pediatrics. 2018; e20173459 DOI10.1542/peds.2017-3459.