Weight Management & Satiety

Nutrition Close-Up, Fall 2015 (pdf, 1.9 MB)

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Associations between egg consumption and cardiovascular risk factors depends on the other foods and beverages consumed.

Researchers compared cardiovascular risk among adult egg eaters to those who did not report eating an egg or egg dish during their 24-hour food recall in the 2001-2008 U.S. National Health and Nutrition Examination Survey (NHANES) (Nicklas, 2014). Egg eaters were additionally sub-grouped based on overall diet patterns characterized using percent energy intake from food groups, resulting in a total of 8 diet patterns (i.e., no egg diet pattern and 7 diet patterns among egg eaters).

Continue reading “When It Comes To Health, Diet Patterns Matter More Than How Many Eggs You Eat” →

Men and women with greater dietary protein intakes were more likely to have lower body mass index and waist circumference, and higher HDL-cholesterol.

A cross-sectional study of over 23,000 adults from the NHANES, 2001-2010, examined usual protein intakes [expressed as g/kg body weight (BW) per day], and trends for associations with cardiometabolic risk factors including blood pressure, glucose, insulin, cholesterol, and triglycerides stratified by weight status using cut-points of >18.5, >25 and >30 kg/m² for normal weight, overweight, and obese, respectively [Pasaikos, 2015]. Subjects were separated into deciles of usual protein intake, which ranged from 0.69 g/kg BW in the lowest decile to 1.51 g/kg BW in the highest decile.

Analyses indicated that a higher protein intake (g/kg BW) was associated with a lower body mass index (BMI) and lower waist circumference in the total population, with a more pronounced effect in overweight and obese than in normal weight individuals. Further, there was a positive association between protein intake and HDL-cholesterol in all weight classifications, which persisted after adjustment for multiple variables including energy and macronutrient intake. There were no other associations identified between protein intake and other cardiometabolic risk factors.

The authors noted a “robust association between dietary protein and HDL cholesterol”. Results showed that

“HDL cholesterol concentrations for those who consumed ~1.5 g protein/kg BW were ~15% higher than those who consumed protein at or below the RDA, particularly in overweight individuals.”

In summary, the authors stated that this study

“demonstrates the health-related benefits associated with habitual consumption of dietary protein beyond the RDA. The levels of protein routinely consumed in deciles 6 through 10 (~1.0-1.5 g/kg BW), that were associated with lower waist circumference, BMI, and higher HDL cholesterol are consistent with nationally recognized recommendations (based on nitrogen and skeletal muscle retention) for physically active adults…military personnel…older adults…and individuals attempting weight loss…all of which are higher than the current RDA.”

Reference Citation

Pasiakos, SM, HR Lieberman, and VL Fulgoni. “Higher-protein diets are associated with higher HDL cholesterol and lower BMI and waist circumference in US Adults.” J Nutrition 2015; Mar;145(3):605-14.

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Confusing nutrition messages are often linked to timing of meals and types of foods, but struggling consumers can take action by eating nutritious choices relatively more frequently and earlier in the day.

 Ghadeer Aljuraiban and research colleagues summarized cross-sectional associations between both the frequency and the time of eating, to energy density, nutrient quality (using the NRF9.3 index), and BMI, using data on 2,385 men and women age 40-59 years living in the US and the UK, participating in the International Study on Macro/Micronutrients and Blood Pressure (Aljuraiban, 2015). Note that “[o]nly solid foods were included in calculating energy density, consistent with previous studies that concluded that beverages should be excluded…” because liquids disproportionately affect energy density.

On average, women reported more eating occasions/day than men (5.0 compared to 4.6/day, respectively) and had a lower energy density (kcal/g). Women and men consumed a similar ratio of evening/morning energy intake (3.3 and 3.4 ratio of evening to morning on average).

Overall,

“[P]articipants who ate more frequently and consumed most of their energy earlier in the day (>6 eating occasions/24 hours and ratio of evening/morning energy intake <1.8) had lower energy density, total energy intake, and alcohol intake; higher NRF9.2 [i.e., higher nutrient rich food index], food weight, and fruit intake compared to those who ate fewer eating occasions…and consumed most of their food later in the day…”

BMI was inversely associated with eating occasions (i.e., the more occasions, the lower BMI) and with nutrient density (NRF9.3). As expected, BMI was positively associated with dietary energy density. It was also associated with higher ratio of evening/morning energy intake.

Also from this study, it appears that those eating more frequently, but earlier in the day, tend to eat more low-fat/fat-free dairy, cooked vegetables, and fruit (high nutrient dense foods) and less red meat and less beverages overall, but particularly alcohol.

To summarize, the authors concluded by stating

“Our findings demonstrated that lower BMI levels in more frequent eaters are associated with consumption of lower dietary energy density and higher nutrient quality foods. Modifying eating behavior through more frequent meals of low dietary energy density and high nutrient quality may be an important approach to control epidemic obesity.”

Reference Citation

GS Aljuraiban, Q Chan, LM Oude Griep, IJ Brown, ML Daviglus, J Stamler, L Van Horn, P Elliott, and GS Frost for the INTERMAP Research Group. “The impact of eating frequency and time of intake on nutrient quality and body mass index: The INTERMAP study, a population-based study” Journal of the Academy of Nutrition and Dietetics. 2015;Vol. 115(4):528-535.

Robyn Kievit Kirkman, FNP-BC, RDN, LDN, CSSD, CEDRD, is a dietitian in private practice in Boston & Concord, MA, and also works as a nurse practitioner. She serves as a health professional advisor to the Egg Nutrition Center.

Views expressed by the author may not be those of the Egg Nutrition Center.

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ENC likes to provide the opportunity for up and coming investigators to showcase their research, and today’s post comes from a student of Jamie I. Baum, PhD, Assistant Professor of Nutrition at the University of Arkansas. Dallas Johnson is a graduate of the University of Arkansas receiving a B. S. in Biology. He now works as a research associate in Dr. Jamie Baum’s lab conducting projects focusing role of dietary protein on energy metabolism and metabolic health. Dallas has recently been accepted in to medical school and will be starting in the fall of 2015.

More than one third of Americans are obese, making obesity a very real public health concern (1). Obesity comes with a multitude of health issues including cardiovascular disease, elevated risk of diabetes and metabolic syndrome. While individual situations can vary greatly, increasing protein levels in the diet has been shown to be an effective way to help combat obesity (2).

One of the ways protein can affect daily calorie intake is through its ability to increase satiety. Although high carbohydrate meals can increase satiety acutely, meals higher in protein (20-30% of the total energy provided by the meal) have been shown to have a more prolonged effect on satiety.  According to a study by Westerterp-Plantenga et al., published in the British Journal of Nutrition, this feeling of satiety is attributed to the ability of protein to stimulate the release of glucagon-like peptide-1 (GLP-1). Specifically, GLP-1 mediates the so-called “ileal brake”, an inhibitory feedback mechanism which controls the motility of a meal through the gastrointestinal system, and thus slows gastric emptying (3), thus leading to the feeling of being “full.” Moreover, free amino acids are released into the bloodstream following a high protein meal, which can also enhance the feeling of fullness (4).

In addition to inducing satiety, a high protein diet has also been found to impact the body’s daily energy expenditure. Daily energy expenditure can be broken down into different categories.  Active expenditure is the most variable form and results from physical activity. Resting metabolic ratecomprises around 70% of one’s daily calorie use and doesn’t vary much. One of the variants in resting metabolic rate is the total weight of lean tissue (e.g. muscle) in the body (4). Lean tissue can be increased or maintained by engaging in regular resistance exercise and a consistent intake of protein and calories in daily meals (4).

Protein not only has the potential to affect long-term energy expenditure but can also affect calories burned directly after a meal (diet-induced thermogenesis), even more so than other macronutrients (5). This increase in diet-induced thermogenesis is partly due to an enhanced protein turnover rate.  When the body is flooded with more protein than it can handle, it actively oxidizes and eliminates the excess amino acids. This leads to an increase in thermogenesis and the resultant up-regulation of uncoupled protein-2 (UCP2) in the liver and uncoupled protein-1 (UCP1) in brown adipose tissue, in turn, leads to higher energy expenditure (5).  Protein is also an inefficient source of ATP compared to fat and carbohydrate, requiring several stages of metabolism, including urea synthesis, before becoming available for energy production. According to a recent study, up to forty-two percent of the observed increase in energy expenditure following a high-protein, carbohydrate-free meal can be explained by these additional steps and the increase in gluconeogenesis that follows (4).

The battle against obesity is a very complex, multi-faceted issue that includes hormonal balance, genetic makeup and metabolic processes, but evidence from recent and ongoing studies suggests that protein can play an important role in body weight management.

References:

1. Ogden C. L., Carroll, M. D., Kit, B.K., & Flegal K. M. (2014). Prevalence of childhood and adult obesity in the United States, 2011-2012. Journal of the American Medical Association, 311(8), 806-814.

2. Rodriguez, N., & Garlick, P. (2008). Introduction to protein summit 2007: Exploring the impact of high-quality protein on optimal health. The American Journal of Clinical Nutrition, 87, 1551-3.

3. Marathe CS, Rayner CK, Jones KL, Horowitz M. Effects of GLP-1 and incretin-based therapies on gastrointestinal motor function. Exp Diabetes Res. 2011;2011:279530.

4. Westerterp-Plantenga, M., Lemmens, S., & Westerterp, K. (2012). Dietary protein- its role in satiety energetics, weight loss and health. British Journal of Nutrition, 108, S105-S112.

5. Paddon-Jones, D., Matters, R., Wolfe, R., Astrup, A., & Westerterp-Plantenga, M. (2008). Protein, weight management, and satiety. The American Journal of Clinical Nutrition, 87.