Could the Timing of When You Eat, Be Just as Important as What You Eat?

Jan. 29, 2013 — Most weight-loss plans center around a balance between caloric intake and energy expenditure. However, new research has shed light on a new factor that is necessary to shed pounds: timing. Researchers from Brigham and Women’s Hospital (BWH), in collaboration with the University of Murcia and Tufts University, have found that it’s not simply what you eat, but also when you eat, that may help with weight-loss regulation.


 

The study will be published on January 29, 2013 in the International Journal of Obesity.

“This is the first large-scale prospective study to demonstrate that the timing of meals predicts weight-loss effectiveness,” said Frank Scheer, PhD, MSc, director of the Medical Chronobiology Program and associate neuroscientist at BWH, assistant professor of medicine at Harvard Medical School, and senior author on this study. “Our results indicate that late eaters displayed a slower weight-loss rate and lost significantly less weight than early eaters, suggesting that the timing of large meals could be an important factor in a weight loss program.”

To evaluate the role of food timing in weight-loss effectiveness, the researchers studied 420 overweight study participants who followed a 20-week weight-loss treatment program in Spain. The participants were divided into two groups: early-eaters and late-eaters, according to the self-selected timing of the main meal, which in this Mediterranean population was lunch. During this meal, 40 percent of the total daily calories are consumed. Early-eaters ate lunch anytime before 3 p.m. and late-eaters, after 3 p.m. They found that late-eaters lost significantly less weight than early-eaters, and displayed a much slower rate of weight-loss. Late-eaters also had a lower estimated insulin sensitivity, a risk factor for diabetes.

Researchers found that timing of the other (smaller) meals did not play a role in the success of weight loss. However, the late eaters — who lost less weight — also consumed fewer calories during breakfast and were more likely to skip breakfast altogether. Late-eaters also had a lower estimated insulin sensitivity, a risk factor for diabetes.

The researchers also examined other traditional factors that play a role in weight loss such as total calorie intake and expenditure, appetite hormones leptin and ghrelin, and sleep duration. Among these factors, researchers found no differences between both groups, suggesting that the timing of the meal was an important and independent factor in weight loss success.

“This study emphasizes that the timing of food intake itself may play a significant role in weight regulation” explains Marta Garaulet, PhD, professor of Physiology at the University of Murcia Spain, and lead author of the study. “Novel therapeutic strategies should incorporate not only the caloric intake and macronutrient distribution, as it is classically done, but also the timing of food.”


Story Source:

The above story is reprinted from materials provided byBrigham and Women’s Hospital, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. M Garaulet, P Gómez-Abellán, J J Alburquerque-Béjar, Y-C Lee, J M Ordovás, F A J L Scheer. Timing of food intake predicts weight loss effectivenessInternational Journal of Obesity, 2013; DOI: 10.1038/ijo.2012.229
Brigham and Women’s Hospital (2013, January 29). Could the timing of when you eat, be just as important as what you eat?. ScienceDaily. Retrieved January 30, 2013, from http://www.sciencedaily.com/releases/2013/01/130129080620.htm
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Lose Fat Faster Before Breakfast

Jan. 24, 2013 — People can burn up to 20% more body fat by exercising in the morning on an empty stomach, according to new research from Northumbria University.


 

In a study published online in theBritish Journal of Nutrition on January 24, academics sought to find out whether the known benefits of exercising after an overnight fast were undermined by an increased appetite and eating more food later in the day.

Researchers, led by Dr Emma Stevenson and PhD student Javier Gonzalez, asked twelve physically active male participants to perform a bout of treadmill exercise at 10am, either after they had eaten breakfast or in a fasted state having not eaten since the evening before.

Following the exercise all participants were given a chocolate milkshake recovery drink. Later in the day, participants were provided with a pasta lunch which they were asked to consume until they felt ‘comfortably full’. Their lunchtime consumption of energy and fat was assessed and calculated, taking into account the amount of energy and fat burned during the morning period.

The researchers discovered that those who had exercised in the morning did not consume additional calories or experience increased appetite during the day to compensate for their earlier activity.

They also found that those who had exercised in a fasted state burned almost 20% more fat compared to those who had consumed breakfast before their workout. This means that performing exercise on an empty stomach provides the most desirable outcome for fat loss.

Javier Gonzalez, who is currently undertaking a PhD in Exercise and Metabolism, said: “In order to lose body fat we need to use more fat than we consume. Exercise increases the total amount of energy we expend and a greater proportion of this energy comes from existing fat if the exercise is performed after an overnight fast.

“Our results show that exercise does not increase your appetite, hunger or food consumption later in the day and to get the most out of your session it may be optimal to perform this after an overnight fast.”

Dr Emma Stevenson, Senior Lecturer in Sport and Exercise Nutrition and Associate Director of Northumbria University’s Brain, Performance and Nutrition Research Centre, added: “This research is very important in helping to provide practical guidelines relating to food intake to individuals who are exercising to maximise fat mass loss. It must be highlighted that this is a short-term study and we can only speculate on the longer term outcomes of such nutritional practices.”

 

Story Source:

The above story is reprinted from materials provided byNorthumbria University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. Javier T. Gonzalez, Rachel C. Veasey, Penny L. S. Rumbold, Emma J. Stevenson. Breakfast and exercise contingently affect postprandial metabolism and energy balance in physically active malesBritish Journal of Nutrition, 2013; : 1 DOI: 10.1017/S0007114512005582
Northumbria University (2013, January 24). Lose fat faster before breakfast. ScienceDaily. Retrieved January 28, 2013, from http://www.sciencedaily.com/releases/2013/01/130124091425.htm

For Those Short On Time, Aerobic, Not Resistance, Exercise Is Best Bet for Weight And Fat Loss

Jan. 2, 2013 — A new study led by North Carolina researchers has found that when it comes to weight- and fat loss, aerobic training is better than resistance training. The study is believed to the largest randomized trial to directly compare changes in body composition induced by comparable amounts of time spent doing aerobic and resistant training, or both in combination, among previously inactive overweight or obese non-diabetic adults.


 

The study is entitled “Effects of aerobic and/or resistance training on body mass and fat mass in overweight or obese adults”. It is published in the December 2012 edition of the Journal of Applied Physiology published by the American Physiological Society.

Methodology

A total of 234 previously sedentary overweight or obese males and females, age 18-70 years of age, were enrolled in one of three eight-month supervised protocols: aerobic training (AT), resistance training (RT), or a combination (AT/RT). Of the total, 119 participants completed the trials and had complete data for the variables of interest in the article.

Those assigned to aerobic training exercised vigorously, at about 70-85% of maximum heart rate. They exercise approximately 45 minutes three days per week throughout the study period.

Individuals assigned to resistance training also exercised three days a week, completing three sets of 8-12 reps on eight resistance machines that targeted all major muscle groups. Resistance was increased throughout the study to maintain a steady level of challenge as the participants gained strength.

Individuals who were assigned to AT/RT performed all the exercises assigned to both AT and RT groups. At the end of study each enrollee was assessed for weight, body composition, waist circumference, cardiopulmonary fitness and strength compared to their baseline.

Key Findings and Conclusions

The researchers found:

• The groups assigned to aerobic training and aerobic plus resistance training lost more weight than those that did resistance training only. In fact, those who did resistance training only actually gained weight due to an increase in lean body mass.

• Fat mass and waist circumference significantly decreased in the AT and AT/RT groups, but were not altered in RT. However, measures of lean body mass significantly increased in RT and AT/RT, but not in AT. The finding suggest that aerobic exercise is more effective in reducing these measures.

• Lean body mass increased with both RT and AT/RT, but not AT. Having the benefit to of both modes of exercise allowed AT/RT to decrease body fat percent significantly more than either AT or RT due to decreased fat mass combined with increased lean body mass.

Importance of the Findings

According to Leslie H. Willis, an exercise physiologist at Duke University Medical Center and the study’s lead author, “Given our observations, it may be time to seriously reconsider the conventional wisdom that resistance training alone can lead to weight and fat loss.”

Willis added, “If increasing muscle mass and strength is a goal, then resistance training is required. However, the majority of Americans could experience health benefits due to weight and fat loss. The best option in that case, given limited time for exercise, is to focus on aerobic training. When you lose fat, it is likely you are losing visceral fat, which is known to be associated with cardiovascular and other health benefits.”

In addition to Leslie Willis, the study was conducted by Cris A. Slentz, Lori A. Bateman, Lucy W. Piner, Connie W. Bales and William E. Kraus of the Duke University Medical Center; and Joseph A Hourmard and A. Tamlyn Shields of East Carolina University.


Story Source:

The above story is reprinted from materials provided byAmerican Physiological Society (APS), via Newswise.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. L. H. Willis, C. A. Slentz, L. A. Bateman, A. T. Shields, L. W. Piner, C. W. Bales, J. A. Houmard, W. E. Kraus. Effects of aerobic and/or resistance training on body mass and fat mass in overweight or obese adultsJournal of Applied Physiology, 2012; 113 (12): 1831 DOI:10.1152/japplphysiol.01370.2011
 

 

American Physiological Society (APS) (2013, January 2). For those short on time, aerobic, not resistance, exercise is best bet for weight- and fat loss. ScienceDaily. Retrieved January 3, 2013, from http://www.sciencedaily.com/releases/2013/01/130102172945.htm