Past Week in Nutrition Science


This is an overview of everything new and interesting that happened in nutrition science in the past week, from last Friday (Sep 25th) until today (Oct 2nd).


Past Week in Nutrition Science (Sep 25th – Oct 2nd)

Research Review

This week, we reviewed two new studies. One was on the effects of saturated fat from meat and cheese on blood lipids, while the other was about the effects of different fruits and vegetables on weight change.


Link: Effects of Saturated Fat From Meat and Cheese on Blood Lipids

Study: Thorning et al. Diets With High-Fat Cheese, High-Fat Meat, or Carbohydrate on Cardiovascular Risk Markers in Overweight Postmenopausal Women: A Randomized Crossover Trial. American Journal of Clinical Nutrition 2015.

Summary: This randomized controlled trial looked at the effects of saturated fat from high-meat and high-cheese diets on blood lipids and lipoproteins. The control group followed a low-fat, high-carb diet.

In this study, the high saturated fat diets had very little effects, except that they increased HDL cholesterol and apolipoprotein-A1, the lipoprotein that carries HDL cholesterol in the blood.


Link: Do All Fruits and Vegetables Help You Lose Weight?

Study: Bertoia et al. Changes in Intake of Fruits and Vegetables and Weight Change in United States Men and Women Followed for Up to 24 Years: Analysis from Three Prospective Cohort Studies. PLOS Medicine 2015.

Summary: This paper analyzed data from 3 observational studies with a total of 133,468 people. It looked at changes in intake of specific fruits and vegetables and effects on body weight.

They found that all fruits were associated with weight loss, especially berries. Vegetables were also associated with weight loss, except for starchy vegetables like potatoes, corn and peas – which were associated with weight gain.

Vegetables that were both high in fiber and had a low glycemic load (GL) were more strongly associated with weight loss over time.

New Studies From Around The Web

A ton of interesting studies were published in the past week, with new releases from the American Journal of Clinical Nutrition, Journal of Nutrition and British Journal of Nutrition.

Here is an overview of the most interesting studies, organized by category.

Obesity and Weight Loss

Frequent Self-Weighing with Electronic Graphic Feedback to Prevent Age-Related Weight Gain in Young Adults.

This randomized controlled trial showed that weighing oneself every day with Wi-Fi scales and receiving graphic feedback via e-mail prevented age-related weight gain in young college students. The intervention group lost 0.5 kg (1.1 lb), while the control group gained 1.1 kg (2.4 lbs) over 1 year.

Sympathetic Neuro-adipose Connections Mediate Leptin-Driven Lipolysis.

This study suggests that the lipolytic (fat-burning) effects of the hormone leptin are mediated by sympathetic nerves in fat tissue.

The Human Circadian System Has a Dominating Role in Causing the Morning/Evening Difference in Diet-Induced Thermogenesis.

This randomized crossover study showed that diet-induced thermogenesis (DIT) was 44% lower in the evening compared to morning, which was mediated by the circadian system (the body’s internal clock). Eating food in the evening or at night may cause weight gain compared to eating it in the morning, when DIT is higher.

Metabolic adaptation to caloric restriction and subsequent refeeding: the Minnesota Starvation Experiment revisited.

This was an analysis from the Minnesota Starvation Experiment looking at metabolic adaptation to severe calorie restriction and subsequent refeeding. We will be reviewing this study in detail next week.

Examination of central body fat deposition as a risk factor for loss-of-control eating.

This study found that increased body fat in the abdominal cavity (visceral fat) was linked to increased body dissatisfaction and increased risk of loss-of-control eating. Depositing body fat “centrally” may raise the risk of eating disorders.

Breakfasts Higher in Protein Increase Postprandial Energy Expenditure, Increase Fat Oxidation, and Reduce Hunger in Overweight Children from 8 to 12 Years of Age.

This randomized crossover study found that a high-protein breakfast increased metabolism and fat burning and reduced hunger in both normal weight and overweight children.

Elevated BMI and Male Sex Are Associated with Greater Underreporting of Caloric Intake as Assessed by Doubly Labeled Water.

This study found that males, and those with a higher BMI, under-reported their calorie intake to a greater extent.

Cardiovascular Health

Longitudinal association of dairy consumption with the changes in blood pressure and the risk of incident hypertension: the Framingham Heart Study.

This analysis from the Framingham Heart Study Offspring Cohort found that yogurt intake was associated with reduced risk of developing high blood pressure. It also found that total dairy intake and total low-fat/fat-free dairy intake were linked to decreased diastolic blood pressure.

The Effect of a Dietary Portfolio Compared to a DASH-Type Diet on Blood Pressure.

This 24-week randomized controlled trial found that a cholesterol-lowering diet with soy protein, viscous fiber and nuts caused slightly greater reductions in blood pressure than a DASH-type diet.

Effect of improving dietary quality on carotid intima media thickness in subjects with type 1 and type 2 diabetes: a 12-mo randomized controlled trial.

This 12-month randomized controlled trial found that recommendations to increase fruit and vegetable intake slowed the progression of atherosclerosis in the carotid arteries in individuals with type 1 and type 2 diabetes.

Sugar-sweetened beverage consumption and incident hypertension: a systematic review and meta-analysis of prospective cohorts.

This meta-analysis of 6 observational studies found that drinking sugar-sweetened beverages was linked to a 12% greater risk of developing high blood pressure. Each single serving per day was linked to an 8.2% greater risk.

Higher Plasma Phospholipid n–3 PUFAs, but Lower n–6 PUFAs, Are Associated with Lower Pulse Wave Velocity among Older Adults.

This observational study found that higher levels of omega-6 fatty acids in the blood were linked to increased stiffness of arteries, while levels of omega-3 fatty acids were linked to decreased stiffness.

Insulin Resistance and Metabolic Syndrome

Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis.

This meta-analysis of randomized controlled trials found that a paleolithic diet caused greater short-term improvements in symptoms of metabolic syndrome compared to standard nutrition guidelines.

Type and amount of dietary protein in the treatment of metabolic syndrome: a randomized controlled trial.

This randomized controlled trial compared modified DASH diets high in either animal or plant protein in overweight adults with metabolic syndrome. Both diets were effective and there was no difference between plant or animal protein.

Consumption of Yogurt, Low-Fat Milk, and Other Low-Fat Dairy Products Is Associated with Lower Risk of Metabolic Syndrome Incidence in an Elderly Mediterranean Population.

This analysis from the PREDIMED study found that low-fat dairy, low-fat yogurt, low-fat milk and whole-fat yogurt were linked to decreased risk of metabolic syndrome. However, cheese was linked to increased risk.

Blood Sugar Control and Diabetes

Comparison of low- and high-carbohydrate diets for type 2 diabetes management: a randomized trial.

This 52-week randomized controlled trial in 115 obese individuals with type 2 diabetes compared calorie-restricted low-carb and high-carb diets. Both diets caused weight loss and improved blood sugar control. The low-carb diet had greater effects on blood lipids, blood sugar stability and caused a greater reduction in diabetes medication requirements.

A single serving of caffeinated coffee impairs postprandial glucose metabolism in overweight men.

This study found that a single serving of caffeinated coffee raised blood sugar levels in overweight men.


Dietary fiber intake and risk of colorectal cancer and incident and recurrent adenoma in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.

This observational study did not find a statistically significant reduction in colorectal cancer based on total fiber intake. However, it did find a reduction in distal colorectal cancer risk and incident colorectal adenoma.

Vegetarian and Vegan Diets

Cross-sectional and longitudinal comparisons of metabolic profiles between vegetarian and non-vegetarian subjects: a matched cohort study.

This observational study found that lacto-ovo vegetarians, lacto-vegetarians and vegans had reduced obesity, blood pressure and blood sugar compared to non-vegetarians. However, the vegetarians and vegans had lower HDL levels.

Foods and Food Groups

Consumption of Honey, Sucrose, and High-Fructose Corn Syrup Produces Similar Metabolic Effects in Glucose-Tolerant and -Intolerant Individuals.

This randomized crossover trial found that 50 grams of honey, sucrose and high-fructose corn syrup for 14 days had similar effects on inflammation, blood sugar control and blood lipids. All 3 increased blood triglycerides, but only increased blood sugar and inflammatory markers in individuals with insulin resistance.

Efficacy of fish intake on vitamin D status: a meta-analysis of randomized controlled trials.

This meta-analysis of randomized controlled trials found that fish (especially fatty fish) increased blood levels of vitamin D. On average, increased fish intake increased blood levels by 4.4 nmol/mL, but reached 8.3 nmol/L in the longer-term studies.

Systematic review of the effect of processing of whole-grain oat cereals on glycaemic response.

This systematic review compared different types of whole-grain oats cereals and their effects on blood sugar levels. Steel-cut oats, large-flake oats, muesli and granola had much smaller effects on blood sugar levels than than quick-cooking oats and instant oatmeal.

Impact of palm date consumption on microbiota growth and large intestinal health: a randomised, controlled, cross-over, human intervention study.

This study found that palm dates did not change levels of gut bacteria. However, the dates did increase bowel movements and stool frequency and reduced fecal genotoxicity, which may indicate reduced risk of colon cancer.


Does vitamin-D intake during resistance training improve the skeletal muscle hypertrophic and strength response in young and elderly men? – a randomized controlled trial.

This randomized controlled trial found no effect of vitamin D supplementation on muscle hypertrophy or muscle strength over 12 weeks in young or elderly individuals. However, there was some difference in muscle quality in elderly and fiber type morphology in young individuals.

Effects of intraduodenal infusion of the branched-chain amino acid leucine on ad libitum eating, gut motor and hormone functions, and glycemia in healthy men.

Infusing the amino acid leucine into the duodenum of lean men reduced calorie intake by 13%, increased blood levels of cholecystokinin (CCK) and reduced blood sugar and insulin levels.

The effect of melatonin treatment on postural stability, muscle strength, and quality of life and sleep in postmenopausal women: a randomized controlled trial.

This randomized controlled trial found that melatonin supplementation for 12 months had no effects on postural balance, risk of falls, muscle strength, quality of life or sleep in postmenopausal women. However, there was a non-significant trend towards improved sleep in women who had sleep disturbances at the beginning of the study.

Effects of a quercetin-rich onion skin extract on 24 h ambulatory blood pressure and endothelial function in overweight-to-obese patients with (pre-)hypertension: a randomised double-blinded placebo-controlled cross-over trial.

This randomized controlled trial found that quercetin from onion skin slightly reduced systolic blood pressure (-3.6 mmHg) in individuals with high blood pressure, but not in individuals with normal blood pressure.

Cocoa flavanol intake improves endothelial function and Framingham Risk Score in healthy men and women: a randomised, controlled, double-masked trial: the Flaviola Health Study.

This study found that cocoa flavanols significantly improved endothelial function. They also lowered blood pressure and LDL cholesterol, while increasing HDL cholesterol.

Vitamin E function and requirements in relation to PUFA.

A review that discusses how vitamin E requirements may be increased when people increase their intake of polyunsaturated fatty acids.

Muscle Building

Role of insulin in the regulation of human skeletal muscle protein synthesis and breakdown: a systematic review and meta-analysis.

This is a review of the effects of the hormone insulin on skeletal muscle protein synthesis and breakdown.

Differences in postprandial protein handling after beef compared with milk ingestion during postexercise recovery: a randomized controlled trial.

This crossover randomized controlled trial of 12 young men found that dairy protein had a greater effect on muscle protein synthesis in the 0-2 hour post-exercise phase, but there was no net difference over the 0-5 hour post-exercise phase.

Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial.

This randomized controlled trial found that supplementing with collagen peptides improved body composition and increased muscle strength in elderly men with sarcopenia, when combined with resistance training.

Fertility and Pregnancy

Association between serum folate and vitamin B-12 and outcomes of assisted reproductive technologies.

Women with high blood levels of folate and vitamin B12 had much higher (62% and 104%, respectively) rates of successful live births using assisted reproductive technology (ART) treatment.

Maternal prepregnancy obesity and cause-specific stillbirth.

This study found that overweight, obese and severely obese women had 40%, 80% and 100% greater risk of stillbirth, respectively, compared to lean women.

Aging and Longevity

Dietary inflammatory index and telomere length in subjects with a high cardiovascular disease risk from the PREDIMED-NAVARRA study: cross-sectional and longitudinal analyses over 5 y.

This study found that a diet with a high dietary inflammation index (DII) was associated with a shortening of telomeres. This indicates that an inflammatory diet can accelerate aging, and that an anti-inflammatory diet may slow aging.

Written by Aline Pilani

Hey. I’m Aline Pilani. I am a certified personal trainer and nutritionist and have spent the last 10 years of my life helping people losing weight, increase their health and confidence, and I truly want to do the same for you.

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