Written by Jessica Patella, ND. The research indicated that the timing of the main meal of the day may be the most important factor in weight loss and should be considered for weight loss therapies.
Recent research studies link energy regulation to the circadian clock at behavioral, physiological and even molecular levels (2-4). This research indicates that the timing of eating may play a significant role in weight regulation (1, 5). The first longitudinal study in humans found that the timing of food intake relates to effective weight loss in humans (1).
The study included 420 overweight and obese Spanish adults who were voluntarily attending nutrition classes to lose weight based on the Mediterranean diet (1). All the participants attended weekly 60-minute sessions, which included information on the Mediterranean diet, nutritional education, physical activity intervention and cognitive-behavioral techniques (positive reinforcement, self-monitoring, preventing relapse) for 5 months. Once they achieved their weight loss goal, the participants followed a 5-month maintenance period, meeting every 2 weeks to monthly. No advice was given to the participants regarding food timing and when to eat their largest meals (1).
Dietary intake during the study was measured by diet diary records, where the participant recorded their daily food intake, including measuring and weighing foods, as well as the time of day each meal was consumed. One week was chosen at random to analyze for the study (1).
In this Spanish population, lunch was the meal with the greatest caloric intake (40% of total daily caloric intake) for the day. After analyzing the data, the results showed that late lunch eaters lost significantly less weight than early eaters.
| Early eaters, before 3pm ( n=202) | Late eaters, after 3 pm (n=200) | Significance (P-value) |
|
|---|---|---|---|
| Total weight loss (average in pounds) | 21.83 | 16.97 | 0.008 |
| Weight loss (% of initial weight) | 11.3 | 9.0 | 0.006 |
| Weekly weight loss (average in pounds) | 1 | 0.79 | 0.026 |
The late lunch eaters also displayed a slower rate of weight loss starting after the 5th week of treatment, and this difference was maintained during the rest of the study (p=0.002).
The most interesting finding was that calorie intake, total calories burned and physical activity were similar between the early and late lunch eaters. Also, no significant differences were found between the groups in appetite hormones or sleep duration (1).
It was also observed that late eaters ate breakfast with less calories than early lunch eaters (% daily energy intake; p=0.031) and skipped breakfast more frequently than early eaters (6.6% vs 2.6%; p=0.039) (1).
In conclusion, eating later may impair the success of weight loss therapy (1). This has been previously shown in animal studies but these findings are the first to study timing of eating on weight loss in humans (1). The research indicated that the timing of the main meal of the day may be the most important factor in weight loss and should be considered for weight loss therapies (1). Future research might consider looking at timing of meals for the US population that typically consumes the most calories in the evening for dinner.
Source: Garaulet, Marta, et al. “Timing of food intake predicts weight loss effectiveness.” International journal of obesity 37.4 (2013): 604-611.
Copyright © 2013, Rights Managed by Nature Publishing Group
Posted February 10, 2016.
Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health. She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians. Visit her website at www.awarenesswellness.com.
References:
- Garaulet M, et al. Timing of food intake predicts weight loss effectiveness. Int J Obes (Lond). 2013 April; 37(4): 604-611.
- Oishi K, et al. CLOCK is involved in the circadian transactivation of peroxisome-proliferator-activated receptor alpha (PPARalpha) in mice. Biochem J 2005; 386:575-581.
- Turek FW, et al. Obesity and metabolic syndrome in circadian clock mutant mice. Science. 2005; 308:1043-1045.
- Froy O. Metabolism and circadian rhythms—implications for obesity. Endocr Rev. 2010; 31:1-24.
- Arble DM, et al. Circadian timing of food intake contributes to weight gain. Obestiy (Silver Spring). 2009; 17:2100-2102.
