Thursday, 19 February 2015

When you have your main meal affects your overall weight loss…...

There have been numerous studies in relation to overall caloric consumption leading to weight loss, however, could there be another important factor to consider?
 Besides the obvious, total amount of energy consumed vs energy expelled, the timing of meals throughout the day has been proven to effect biochemical markers, fat mobilization and consequently weight loss. It has been proven by Garaulet et al 2013, that timing of meals has an effect on weight loss independent of the overall caloric consumption. “In 420 overweight/obese patients undergoing a 20-week weight-loss diet, those who ate their main meal late lost significantly less weight than early eaters. This difference in weight loss success was not explained by differences in caloric intake, macronutrient distribution, or energy expenditure”. 
So what is the justification in avoiding dinner three hours before bed?
A study by Bandin et al 2014, looked at how meal timing affected glucose tolerance, substrate oxidation and circadian (internal body clock) related variables. They concluded by eating a meal close to bedtime, it decreased resting-energy expenditure, decreased fasting carbohydrate oxidation, decreased glucose tolerance, blunted daily profile in free cortisol concentrations and decreased thermal effect of food. 
Another study by Watanabe et al 2014, considered the chrononutrition viewpoint. Chrononutrition explains nutrition in terms of chronobiology and considers the effects of diurnal rhythms, thereby providing new perspectives in nutrition research (Ramsay et al, 2007). Chrononutrition considers the following three components: timing of meals, speed of eating, and the order of food consumption during a meal. Watanabe et al, concluded that the evening is the period in which one can easily gain weight due to the BMAL1 gene (a gene responsible for glucose metabolism and muscle insulin sensitivity), being most active in the period from 10pm to 2am. So basically, the later a meal is eaten, the more strongly the BMAL1 gene is activated and the more likely it is to cause an accumulation of internal fat. 
Is skipping breakfast beneficial to weight loss?
Watanabe et al, 2014, also compared weight gain in individuals who ate dinner within three hours prior to sleeping to those who skipped breakfast altogether. Not surprisingly, both groups gained more weight than the control group and the group who skipped breakfast gained the greater amount of weight. 
“Esquirol et al reported that people who skip breakfast have a 3.4-fold greater risk of developing metabolic syndrome compared with those who eat dinner less than three hours before bedtime and that people who eat snacks at night have 2.6 times the risk of having metabolic syndrome compared to those who do not eat snacks at night”. 
But why? 
There are four lines of evidence which suggest why skipping breakfast is not beneficial:
  1. Skipping breakfast can cause not only a decrease in physical activities in the morning but also a decrease in total energy expenditure which can result in the development of obesity.
  2. A far-infrared radiation thermograph test that measures thermal release from the body, showed that participants who skip breakfast have a low body temperature and decreased energy metabolism. 
  3. While skipping meals reduces overall calorie consumption, it results in blood sugar level spikes. This means forgoing breakfast can cause a decrease in serum blood sugar concentrations, resulting in the breakdown of muscle tissue via the gluconeogenic pathway as a means to provide glucose for the brain; the decrease in muscle volume leads to a subsequent decrease in physical strength. Which consequently results in a decrease of basic metabolism due to the decrease in muscle volume. 
  4. When individuals are hungry, they can conserve energy by limiting physical activities, which can result in a condition whereby the body does not lose weight but instead gains weight easily.

Take home message
Basically, to avoid excessive weight gain, eat breakfast, avoid eating fatty foods particularly at night and avoid eating three hours prior to going to bed. 

References:

Bandin, C., Scheer, F.A., Luque, A.J., Avila-Gandia, V., S, Zamora., Madrid, J.A., Gomez-
            Abellan, P., Garaulet, M., 2014, Meal timing affetcs glucose tolerance, substrate 
           oxidation and circadian-related variables: A randomized, crossover trial, International 
           Journal of Obesity, 10.1038
Esquirol, Y., Bongard, V., Mabile, L., 2009, Shift work and metabolic syndrome: respective  
                impacts of job strain, physical activity, and dietary rhythms, Chronobiology Int,  26: 
                544–559. 

Garaulet, M., Gomez-Abellan, P., Alburquerque-Bejer, Juan., Lee, Y., Ordovas,   
          J.M., Scheer, F.A., 2013, Timing of food intake predicts weight loss 
          effectiveness, International Journal of Obesity, 37(4):604-611

Ramsey, K.M., Marcheva, B., Kohsaka, A., Bass, J., 2007, The clockwork of metabolism, 
                  Annual Review of Nutrition, 27:219-40

Watanabe, Y., Saito, I., Henmi, I., Yoshimura, K., Maruyama, K., Yamauchi, K., 
                Matsuo, T., Kato, T., Tanigawa, T., Kishida, T., Asada, Y., 2014, Skipping 
                Breakfast is Correlated with Obesity, Journal of Rural Medicine, 9(2):51-58