Tag Archives: Diet Studies

Studies: 4- And 6-Hour Time-Restricted Eating (TRE) Diets, No Food Limits Result In Weight Loss

UIC Chicago Illinois
University of Illinois, Chicago (July 15, 2020)

“The findings of this study are promising and reinforce what we’ve seen in other studies — fasting diets are a viable option for people who want to lose weight, especially for people who do not want to count calories or find other diets to be fatiguing,” Varady said. 

…participants in both daily fasting groups reduced calorie intake by about 550 calories each day simply by adhering to the schedule and lost about 3% of their body weight. The researchers also found that insulin resistance and oxidative stress levels were reduced among participants in the study groups when compared with the control group.

4- And 6-Hour Time Restricted Eating TRE DietsTwo daily fasting diets, also known as time-restricted feeding diets, are effective for weight loss, according to a new study published by researchers from the University of Illinois at Chicago.

The study reported results from a clinical trial that compared a 4-hour time-restricted feeding diet and a 6-hour time-restricted feeding diet to a control group.

“This is the first human clinical trial to compare the effects of two popular forms of time-restricted feeding on body weight and cardiometabolic risk factors,” said Krista Varady, professor of nutrition at the UIC College of Applied Health Sciences and corresponding author of the story.

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Diet Studies: Benefits Of “Time-Restricted Eating” (TRE) Improve With Greater Time Restriction

From iScience / Cell.com (June 26, 2020):

iScience June 26 2020…the beneficial effects of TRE are dose dependent, with greater reductions in body weight, fat mass, and improvement in glucose tolerance when a 9-h protocol was implemented versus 12 and 15 h. The optimal TRE time frame to recommend for people has not been tested. Clear improvements have been noted after 6-, 8-, 9-, and 10-h protocols. It is likely that the greater time restriction would result in greater weight losses, which may maximize the metabolic benefits.

Eating out of phase with daily circadian rhythms induces metabolic desynchrony in peripheral metabolic organs and may increase chronic disease risk. Time-restricted eating (TRE) is a dietary approach that consolidates all calorie intake to 6- to 10-h periods during the active phase of the day, without necessarily altering diet quality and quantity.

Time-Restricted Eating

TRE reduces body weight, improves glucose tolerance, protects from hepatosteatosis, increases metabolic flexibility, reduces atherogenic lipids and blood pressure, and improves gut function and cardiometabolic health in preclinical studies. This review discusses the importance of meal timing on the circadian system, the metabolic health benefits of TRE in preclinical models and humans, the possible mechanisms of action, the challenges we face in implementing TRE in humans, and the possible consequences of delaying initiation of TRE.

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Neuroscience: High-Sugar Diets Suppress Dopamine, Leading To Overeating

From Phys.org/Univ. of Michigan (June 9, 2020):

High-Sugar Diet Dampens Release of Dopamine Causing Overeating - Univ of Michigan - Credit Christina May and Monica Dus“On a high-sugar diet, we find that the fruit flies’ dopaminergic neurons are less active, because the high sugar intake decreases the intensity of the sweetness signal that comes from the mouth,” Dus said. “Animals use this feedback from dopamine to make predictions about how rewarding or filling a food will be. In the high-sugar diet flies, this process is broken—they get less dopamine neuron activation and so end up eating more than they need, which over time makes them gain weight.”

It is well known that consuming food and drink high in sugar is not great for us, but scientists are continuing to unravel the intricacies of how the sweet stuff drives negative health outcomes. The latest finding comes from researchers at the University of Michigan, who through studies in fruit flies have found that excess amounts of sugar can shut down crucial neural circuits linked to regulating satiety, possibly leading to overeating in humans.

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Study: “Intensive Diet And Exercise” Reverses Type 2 Diabetes In 61% Of Patients

From The Lancet Diabetes & Endocrinology (June 2020):

Our findings show that the intensive lifestyle intervention led to significant weight loss at 12 months, and was associated with diabetes remission in over 60% of participants and normoglycaemia in over 30% of participants. The provision of this lifestyle intervention could allow a large proportion of young individuals with early diabetes to achieve improvements in key cardiometabolic outcomes, with potential long-term benefits for health and wellbeing.

The Lancet Diabetes & Endocrinology

Type 2 diabetes is affecting people at an increasingly younger age, particularly in the Middle East and in north Africa. We aimed to assess whether an intensive lifestyle intervention would lead to significant weight loss and improved glycaemia in young individuals with early diabetes.
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Between July 16, 2017, and Sept 30, 2018, we enrolled and randomly assigned 158 participants (n=79 in each group) to the study. 147 participants (70 in the intervention group and 77 in the control group) were included in the final intention-to-treat analysis population. Between baseline and 12 months, the mean bodyweight of participants in the intervention group reduced by 11·98 kg (95% CI 9·72 to 14·23) compared with 3·98 kg (2·78 to 5·18) in the control group (adjusted mean difference −6·08 kg [95% CI −8·37 to −3·79], p<0·0001). In the intervention group, 21% of participants achieved more than 15% weight loss between baseline and 12 months compared with 1% of participants in the control group (p<0·0001). Diabetes remission occurred in 61% of participants in the intervention group compared with 12% of those in the control group (odds ratio [OR] 12·03 [95% CI 5·17 to 28·03], p<0·0001). 33% of participants in the intervention group had normoglycaemia compared with 4% of participants in the control group (OR 12·07 [3·43 to 42·45], p<0·0001).
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Diet Infographic: Most “Macronutrient Diets” Reduce Weight & Blood Pressure In 6 Months (BMJ)

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From a BMJ Study article (April, 2020):

Compared with usual diet, moderate certainty evidence supports modest weight loss and substantial reductions in systolic and diastolic blood pressure for low carbohydrate (eg, Atkins, Zone), low fat (eg, Ornish), and moderate macronutrient (eg, DASH, Mediterranean) diets at six but not 12 months. Differences between diets are, however, generally trivial to small, implying that people can choose the diet they prefer from among many of the available diets (fig 6) without concern about the magnitude of benefits.

Introduction

The worldwide prevalence of obesity nearly tripled between 1975 and 2018.1 In response, authorities have made dietary recommendations for weight management and cardiovascular risk reduction.23 Diet programmes—some focusing on carbohydrate reduction and others on fat reduction—have been promoted widely by the media and have generated intense debates about their relative merit. Millions of people are trying to lose weight by changing their diet. Thus establishing the effect of dietary macronutrient patterns (carbohydrate reduction v fat reduction v moderate macronutrients) and popular named dietary programmes is important.

Biological and physiological mechanisms have been proposed to explain why some dietary macronutrient patterns and popular dietary programmes should be better than others. A previous network meta-analysis, however, suggested that differences in weight loss between dietary patterns and individual popular named dietary programmes are small and unlikely to be important.4 No systematic review and network meta-analysis has examined the comparative effectiveness of popular dietary programmes for reducing risk factors for cardiovascular disease, an area of continuing controversy.

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Obesity Study: “Late Night Snacking” Older Adults – Higher Fat Levels Than Early Eaters On Same Diet

From a PLOS Biology Journal study (Feb 20, 2020):

Snacking Before you sleep Keeps on the Fat PLOS Biology April 2020
Schematic: Late-evening snacking interacts with the circadian rhythm of metabolism to inhibit LO.

The major finding of this study is that the timing of feeding over the day leads to significant differences in the metabolism of an equivalent 24-h nutritional intake. Daily timing of nutrient availability coupled with daily/circadian control of metabolism drives a switch in substrate preference such that the late-evening Snack Session resulted in significantly lower LO compared to the Breakfast Session. 

Developed countries are experiencing an epidemic of obesity that leads to many serious health problems, foremost among which are increasing rates of type 2 diabetes, metabolic syndrome, cardiovascular disease, and cancer. While weight gain and obesity are primarily determined by diet and exercise, there is tremendous interest in the possibility that the daily timing of eating might have a significant impact upon weight management [13]. Many physiological processes display day/night rhythms, including feeding behavior, lipid and carbohydrate metabolism, body temperature, and sleep.

PLOS Biology StudiesThese daily oscillations are controlled by the circadian clock, which is composed of an autoregulatory biochemical mechanism that is expressed in tissues throughout the body and is coordinated by a master pacemaker located in the suprachiasmatic nuclei of the brain (aka the SCN [1,4]). The circadian system globally controls gene expression patterns so that metabolic pathways are differentially regulated over the day, including switching between carbohydrate and lipid catabolism [1,3,59]. Therefore, ingestion of the same food at different times of day could lead to differential metabolic outcomes, e.g., lipid oxidation (LO) versus accumulation; however, whether this is true or not is unclear.

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Study: Maintaining Weight Loss Tied To Healthier Eating Routines Formed Over Two-Year Period

From a New York Times online article (March 16, 2020):

New York Times How To Lose Weight and Keep It Off Study March 16 2020“Maintaining weight loss can get easier over time. Over time, less intentional effort, though not no effort, is needed to be successful. After about two years, healthy eating habits become part of the routine. Healthy choices become more automatic the longer people continue to make them. They feel weird when they don’t.”

Among the useful strategies identified in the new study is to keep lower calorie foods like fruits and vegetables more accessible. “We eat what we see,” Dr. Phelan noted. The corollary is equally important: keep high-calorie, less nourishing foods relatively inaccessible and out of sight if not out of the house entirely.

The new study led by Dr. Phelan, professor of kinesiology and public health at California Polytechnic State University, identified habits and strategies that can be keys to success for millions. Yes, like most sensible weight-loss plans, they involve healthful eating and regular physical activity. But they also include important self-monitoring practices and nonpunitive coping measures that can be the crucial to long-term weight management.

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Health Studies: “Spirulina” Improves Cardiovascular (CVD) Risk Factors, Aids In Weight Loss (BMJ)

From a BMJ Open Heart online study (March 8, 2020):

BMJ Open Heart JournalOverall, the evidence in the literature suggests that spirulina improves several well-established CVD risk factors including hyperlipidaemia and seems to provide benefits around weight loss. 

Although caloric restriction and exercise are the mainstay treatments for obesity, spirulina has shown significant benefits in aiding weight loss. The phycocyanin in spirulina contains a light-harvesting chromophore called phycocyanobilin, which is capable of inhibiting nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase, a significant source of oxidative stress in adipocytes playing a key role in inducing insulin resistance and shifting adipokine and cytokine production in hypertrophied adipocytes. Thus, by suppressing adipocyte oxidative stress, spirulina may lead to systemic anti-inflammatory and insulin-sensitising effects.

BMJ Open Heart Journal Study of Spirulina Health benefits March 2020

Spirulina is both a salt and fresh water blue-green algae, which is being increasingly studied recently. Spirulina was initially classified under the plant kingdom due to its rich plant pigments and its ability to photosynthesize, but was later placed into bacterial kingdom (cyanobacteria) due to its genetic, physiological and biochemical makeup. Spirulina grows naturally in high salt alkaline water reservoirs in subtropical and tropical areas of America, Mexico, Asia and Central Africa.

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Studies: “Ultra-Processed Foods” Are 58% Of All Calories In U.S., & Obesity Epidemic’s Major Cause

From a The Guardian online article (Feb 12, 2020):

What characterizes ultra-processed foods is that they are so altered that it can be hard to recognize the underlying ingredients. These are concoctions of concoctions, engineered from ingredients that are already highly refined, such as cheap vegetable oils, flours, whey proteins and sugars, which are then whipped up into something more appetizing with the help of industrial additives such as emulsifiers. 

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From a MedPage Today online article (March 7, 2020):

The top ultra-processed foods by calorie intake were breads, beverages, cakes, Ultra-Processed Diet and Unprocessed Diet Infographiccookies and pies, salty snacks, frozen and shelf-stable dishes, pizza, and breakfast cereals.

Altogether, ultra-processed foods accounted for 58% of all calories in the U.S. diet and nearly 90% of all added sugars.

They divided foods into four categories:

  • Unprocessed or minimally processed foods: Fresh, dry, or frozen fruits or vegetables, grains, legumes, meat, fish, and milk
  • Processed culinary ingredients: Table sugar, oils, fats, salt, and other substances extracted from foods or from nature and used in kitchens to make culinary preparations
  • Processed foods: Foods manufactured with the addition of salt, sugar, or other substances of culinary use to unprocessed or minimally-processed foods, such as canned food, simple breads, and cheese
  • Ultra-processed foods: Formulations of several ingredients that — besides salt, sugar, oils, and fats — include food substances not used in culinary preparations, in particular, flavors, colors, sweeteners, emulsifiers, and other additives used to imitate sensory qualities of unprocessed or minimally-processed foods and their culinary preparations or to disguise undesirable qualities of the final product

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Health Studies: “Habitual” Supplementation Of Fish Oil (Omega-3) Lowers “All Cause Mortality” (BMJ)

From a BMJ Research study (March 4, 2020):

The BMJ podcastHabitual fish oil supplementation is associated with a 13% lower risk of all cause mortality, a 16% lower risk of CVD mortality, and a 7% lower risk of CVD events among the general population

Fish oil is a rich source of long chain omega 3 fatty acids, a group of polyunsaturated fats that primarily include eicosapentaenoic acid and docosahexaenoic acid. Initially, these compounds were recommended for daily omega 3 fatty acid supplementation for the prevention of cardiovascular disease (CVD). Consequently, the use of fish oil supplements is widespread in the United Kingdom and other developed countries.

Omega-3 Fatty Acids Cardiovascular Protection

Several mechanisms could explain the benefits for clinical outcome derived from fish oil supplementation. Firstly, the results of several studies have indicated that supplementation with omega 3 fatty acids has beneficial effects on blood pressure, plasma triglycerides, and heart rate, all of which would exert a protective effect against the development of CVD. Secondly, several trials have shown that omega 3 fatty acids can improve flow mediated arterial dilatation, which is a measure of endothelial function and health. Thirdly, omega 3 fatty acids have been shown to possess antiarrhythmic properties that could be clinically beneficial. Finally, studies have reported that fish oil can reduce thrombosis. Additionally, studies have reported that the anti-inflammatory properties of fish oil could have a preventive role in the pathophysiology of CVD outcomes. Other mechanisms could also be involved to explain the effect of fish oil on CVD outcomes.

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