If you are slimming you’ll lose weight quicker if you confine your carb intake [like pasta, rice, bread, potatoes and fruit] to the evenings. Nutritionists at the Hebrew University of Jerusalem discovered this when they put about sixty overweight policemen and women on a six-month diet.
Intermittent fasting is popular the sports world, not least because of the good results that trainers and athletes have had with this. Take a look at the website of bodybuilder, trainer, consultant and writer Martin Berkhan [leangains.com]. The essence of intermittent fasting is that, instead of trying to divide up the different classes of food you eat, as many dieticians recommend, you concentrate your food intake so that you have relatively long periods of not eating.
There are several ways of doing intermittent fasting. Berkhan advises that you only eat during an eight-hour period of the day, and that you plan your workouts in the first part of that eight-hour period. Your biggest meal, which is also the one containing the most carbs, you plan for after your training session.
That this approach may be effective is suggested by the Israeli study, which will soon be published in Obesity. In the study, test subjects with a BMI of over 30 followed a diet that contained 1300-1500 calories per day. The energy was derived for 20 percent from proteins, 30 percent from fat and 50 percent from carbohydrates.
The control group divided their carb intake over the day; the experimental group ate as much of their carbs as possible at the evening meal. The experimental group ate a breakfast of nuts and low-fat yogurt or cream cheese, and lunch consisted of meat with vegetables.
Concentrating the carbohydrates in the evening meal resulted in a higher weight loss, as the table below shows. The control group lost five kg fat; the experimental group lost seven kg.
The researchers asked the police subjects how hungry they felt, and translated their answers into hunger-satiety scores [H-SSc]. The higher the score, the less the hunger. As the experiment wore on, the sensation of hunger diminished in the experimental group.
Concentrating carb intake in the evening meal was also more healthy, and resulted in an increase in the secretion of the ‘good fat hormone’ adiponectin. Adiponectin helps the muscles to absorb more nutrients from the bloodstream. In addition, the concentration of inflammatory proteins such as CRP, TNF-alpha and Interleukine-6 decreased more in the experimental group than in the control group. The ‘morning’ insulin and glucose levels were lower in the experimental group than in the control group, and their concentration of HDL, ‘good cholesterol’, was higher.
“We have demonstrated improvement in hunger/satiety status, persistence in the weight loss process, better anthropometric outcomes, improved insulin sensitivity, improvement in metabolic syndrome parameters, less inflammation and hormonal changes, following simple carbohydrate manipulation”, the researchers conclude. “Our results provide a scientific basis for proposing possible dietary alternatives that may be beneficial for people suffering from obesity, insulin resistance, and the metabolic syndrome and experiencing difficulties in maintaining a weight loss diet over the long term.”
Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner.
This study was designed to investigate the effect of a low-calorie diet with carbohydrates eaten mostly at dinner on anthropometric, hunger/satiety, biochemical, and inflammatory parameters. Hormonal secretions were also evaluated. Seventy-eight police officers (BMI >30) were randomly assigned to experimental (carbohydrates eaten mostly at dinner) or control weight loss diets for 6 months. On day 0, 7, 90, and 180 blood samples and hunger scores were collected every 4 h from 0800 to 2000 hours. Anthropometric measurements were collected throughout the study. Greater weight loss, abdominal circumference, and body fat mass reductions were observed in the experimental diet in comparison to controls. Hunger scores were lower and greater improvements in fasting glucose, average daily insulin concentrations, and homeostasis model assessment for insulin resistance (HOMA(IR)), T-cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, C-reactive protein (CRP), tumor necrosis factor-? (TNF-?), and interleukin-6 (IL-6) levels were observed in comparison to controls. The experimental diet modified daily leptin and adiponectin concentrations compared to those observed at baseline and to a control diet. A simple dietary manipulation of carbohydrate distribution appears to have additional benefits when compared to a conventional weight loss diet in individuals suffering from obesity. It might also be beneficial for individuals suffering from insulin resistance and the metabolic syndrome. Further research is required to confirm and clarify the mechanisms by which this relatively simple diet approach enhances satiety, leads to better anthropometric outcomes, and achieves improved metabolic response, compared to a more conventional dietary approach.
PMID: 21475137 [PubMed – indexed for MEDLINE]