Our 2-TIP WEIGHT LOSS SERIES
Tip #2
THE WEIGHT LOSS WONDER OF WHEN YOU EAT
Part 2 of 2
-– By Larry Scherwitz and Deborah Kesten –-
Is when you eat the new “why” of weight gain? Recent research by Associate Professor Satchidananda Panda and his research team at the prestigious Salk Institute for Biological Studies in San Diego, CA, suggests this is so. To find out whether obesity and metabolic diseases, such as diabetes, are due solely to a high-fat diet or instead, to the disruption of metabolic cycles based on when one eats, Panda subjected mice to either an “ad lib” (eat any time, day and night) feeding schedule, or eating only during the 8 night time hours when mice typically eat and are most active. To test this, the researchers fed two groups of mice—with the same genes, gender, and age—a 60 percent calories-from-fat diet. The diet was very high fat because it is well-known that a high-fat diet is the best way to induce obesity in mice.
After 100 days, the researchers made an amazing discovery. Despite eating the same amount of calories in the high-fat chow, the mice that ate only during their normal waking hours, at night, maintained a normal weight and metabolism. In contrast, the “ad lib” mice that ate any time—both day and night—developed high cholesterol levels, high blood glucose, high fat deposits in the liver, diminished motor control, and they gained 28 percent more weight than the mice restricted to night eating.1
What’s amazing is that with this high-fat diet, those who ate only during their normal, nocturnal 8-hour cycle maintained their weight and other health measures, such as cholesterol and glucose levels, over three months!
“When”: A New “Why” of Weight Gain
Here’s how Panda explains the benefits of eating during the natural cycle: “Every organ has a clock,” a metabolic cycle that’s critical for, say, cholesterol to breakdown and for glucose to be produced and metabolized. When you eat during your normal sleep cycle—as the “ad lib” mice did—you’re not giving your organs a chance to turn off and rest, and this results in throwing off normal metabolic cycles. But the time-restricted mice on a high-fat diet reaped the rewards of balanced metabolic and physiological rhythms. As a result, they didn’t become obese and they were healthier.
Continues Panda:
“If you fast enough [each day], that itself can be the first line of defense (against weight gain), but if you continue to eat, we don’t get a chance to tap into our stored fat, our stored glycogen, and that storage continues to build up. And I think that contributes to obesity and consequently to diabetes.
“This line of study that we did is going to add another completely new way of thinking about energy balance, diabetes, and obesity. Because it’s not any more calories in and calories out—but when the calorie comes in that matters [italics added]!”2
Were Panda’s groundbreaking results a fluke? To find out, we searched for other studies that could give us some clues. And we found two that replicate and extend Panda’s results. Published in 2009, three years earlier than Panda’s project, Deanna Arble and her colleagues at the Center for Sleep and Circadian Biology at Northwestern University fed two groups of mice the same 60% calories-from-fat diet Panda used, but in Arble’s study, mice were fed for six weeks.3 The other difference is that one group of mice was fed only during their active 12-hour night cycle, while the other group was fed only during the 12-hour daytime cycle—when mice are inactive and don’t typically eat. Arble controlled night and day with light in the laboratory. As with Panda’s study, mice fed “out of rhythm” when it was light, gained significantly more weight than mice fed the same diet during their natural, night time cycle.
The second study we found confirmed yet again that eating based on the body’s natural rhythm can keep our clock genes in rhythm and in turn, keep weight balanced. Published in 2012, this study was conducted in Israel by H. Sherman and colleagues at Hebrew University, and the question the study posed was this: Can long-term restricted feeding (eating based on one’s natural day-night cycle) overcome the disruptive effects a high-fat diet has on the genes that control the timing of our metabolism? To find out, the investigators created four groups of similar mice that would receive the following diets over 18 weeks: 1) high-fat ad libitum (eat any time), 2) high-fat time-restricted, 3) low-fat ad libitum, 4) low-fat time restricted.
The results? Yet again, compared to mice who ate at any time—day and night (ad libitum), mice who ate high-fat fare during their natural cycle, kept their cycle and genes intact and in synchrony; and therefore had a body weight that was 18% lower than their counterparts; at the same time, cholesterol levels were 30% lower; other findings: 10% reduced TNF-alpha levels, and 3.7-fold improved insulin sensitivity.4
The bottom line: Three well-controlled studies show a better metabolic profile for time-restricted feeding. But here’s the amazing finding: Although time-restricted mice fed a high-fat diet consumed the same amount of calories as mice fed an ad libitum low-fat, eat-any-time diet, mice fed the low-fat diet didn’t fare better than “in-cycle” mice fed the high-fat diet. At least in mice, this tells us that restricting eating to the normal, active, eating period is more important to maintaining healthy weight and metabolism than the amount of fat in the diet! Indeed, the Israeli authors summarize their findings by saying, “Taken together, our findings suggest that timing can prevent obesity and rectify the harmful effects of a high-fat diet.”4
Can Human Beings (as Well as Mice) Manage Weight and Health by Eating According to Their Natural Cycle?
We believe that the weight and health benefits that emerge from time-restricted feeding in mice apply to human beings for the following reasons:
- First, the clock genes that control our rhythms are biologically very conservative; that is, they exist in similar structure and function from fruit flies all the way up to mammals, and mice as warm blooded mammals that nurse their young are very close to humans genetically.
- Second, to our knowledge, there have been no time-restricted feeding studies in humans; however, we know that shift workers tend to be more obese than day time workers and that night eaters tend to be more obese than those who do not eat at night.5
- Third, we know that those who eat breakfast tend to weigh less than those who do not eat breakfast.6 This is probably because those who do not eat breakfast tend to snack more, especially at night.
- Fourth, both mice and humans have a master clock in the same area of the brain and both have peripheral clocks in their organs such as the liver and pancreas.7 The master clock is set by light and this clock normally sets the organ clocks. Unlike the master clock, which stays set to light, when you eat at night organ clocks reset to metabolize food, but the master clock does not. This means that the body and brain are then on different schedules, and that being out of rhythm affects hormones that control appetite, metabolic rate, and satiety.
What’s the wondrous dynamic that made it possible for the mice that were restricted from eating during their daytime sleep cycle to escape the negative effects of a high-fat diet? When you eat, the body stores extra calories as body fat; but fast—for several hours (when sleeping), and the body burns fat and breaks down cholesterol into beneficial bile acids.
But eat into the night, and the body does the opposite: instead of metabolizing fat, the body continues to make and store more fat. In turn, this can cause the liver to continue to make glucose, which in turn, causes insulin to rise. And when insulin rises, adipose tissue receptors open, so they can “receive” and store more body fat.
Time-Savvy Tips for Weight Loss
The three studies discussed in this White Paper destroy the notion that a calorie is a calorie, that no matter when you eat it, it has the same effect on your weight. What’s more realistic for being a successful loser is this new perspective: It’s possible you can eat the same amount of calories as you eat now—but can burn them more efficiently—if you are smart about when you eat. Here are some steps you can take to make state-of-the-art science work for your waistline.
Eat breakfast. Take a tip from the most successful losers—those who have successfully lost weight and kept if off for prolonged periods: Eat breakfast every day within one hour of rising. Several studies show that people who eat breakfast weigh less than those who skip breakfast6 even when some breakfast eaters consume more calories than others! Here’s why: Not only does eating breakfast rev up your metabolism, so you’ll burn more calories throughout the day, people who eat breakfast also tend to eat less throughout the day and at night when metabolism typically slows down.
The bottom line: Eating after you wake up in the morning fires up your metabolism and makes your body burn more calories throughout the day than eating at night when your activity is lower.
Know what an optimal breakfast includes. Include complex carbohydrates (fresh whole fruit, veggies, whole grains, legumes, perhaps some nuts (such as walnuts) and seeds (perhaps ground flax), but also high-quality protein foods. A sampling: protein smoothie, yogurt, lean and fresh fish, poultry, etc. Starting the day with protein-rich foods will ward off getting too hungry later in the day, and it’ll keep your blood sugar and insulin levels even.8 (See “Eat Fresh, Weigh Less” for other optimal eating strategies.)
Avoid night eating. When you eat when your body is designed to be “at rest,” instead of restoring itself, your body is hard at work digesting and metabolizing food. When this happens, your body won’t burn (metabolize) calories; rather, they’ll likely be stored as body fat. In other words, food you eat at night makes your genes and organs go to work when they should be resting and restoring. In this way, nighttime eating is a tyrant to your body’s natural rhythm…and weight. Simply put, the body is not made to rapidly burn calories at night.
The Weight Loss Wonder of When You Eat
Timing is everything! To take advantage of your body’s natural rhythm to lose weight and keep it off, time your meals to fit your body’s natural keep-weight-off rhythm. Here, tip #2 and the key concept you need to (strongly!) up your odds of losing weight and keeping it off:
Tip #2
Plan not to eat for 12 hours between your evening meal (at, say, 8 p.m.) and the next day when you’ll be having breakfast in the morning (at, say, 8 a.m.). In other words, eat during your normal waking hours and fast during your normal sleeping hours.
The key take-away: Calories consumed during the day are burned efficiently, while calories consumed at night are more likely to be stored as fat. This means that when you eat may be just as important to your waistline as what and how much you eat. Get with your body’s natural rhythm and you’re more likely to win at weight loss.
For your consideration…
Once you’ve gleaned insights from the “when to eat” discovery we’ve told you about in this post – as well as tip number one on the stages of change – you’re more likely to reap the rewards of our 3 free, scientifically sound, weight-loss programs. We created the programs to give you the re-visioning and understanding you need to redefine the role of food and eating in your life. The Programs accomplish this by empowering you with the practical skills, strategies, tools, and tips you need to transform your relationship to food, eating, and weight, and in the process, find true nourishment.
References:
- Hatori M, Vollmers C, Zarrinpar A, DiTacchio L, Bushong EA, Gill S, et al. Time-restricted feeding without reducing caloric intake prevents metabolic diseases in mice fed a high-fat diet. Cell metabolism. 2012; 15(6): 848-60, PMID 22608008.
- Academy of Nutrition and Dietetics. Possible Drug-Free Intervention for Obesity. U-tube; 2012.
- Arble DM, Bass J, Laposky AD, Vitaterna MH, Turek FW. Circadian timing of food intake contributes to weight gain. Obesity. 2009; 17(11): 2100-2, PMID 19730426.
- Sherman H, Genzer Y, Cohen R, Chapnik N, Madar Z, Froy O. Timed high-fat diet resets circadian metabolism and prevents obesity. FASEB journal : official publication of the Federation of American Societies for Experimental Biology. 2012; 26(8): 3493-502, PMID 22593546.
- Karlsson B, Knutsson A, Lindahl B. Is there an association between shift work and having a metabolic syndrome? Results from a population based study of 27,485 people. Occupational and environmental medicine. 2001; 58(11): 747-52, PMID 11600731.
- Wyatt HR, Grunwald GK, Mosca CL, Klem ML, Wing RR, Hill JO. Long-term weight loss and breakfast in subjects in the National Weight Control Registry. Obes Res. 2002; 10(2): 78-82, PMID 11836452.
- Turek FW, Joshu C, Kohsaka A, Lin E, Ivanova G, McDearmon E, et al. Obesity and metabolic syndrome in circadian Clock mutant mice. Science. 2005; 308(5724): 1043-5, PMID 15845877.
- Astbury NM, Taylor MA, Macdonald IA. Breakfast consumption affects appetite, energy intake, and the metabolic and endocrine responses to foods consumed later in the day in male habitual breakfast eaters. The Journal of nutrition. 2011; 141(7): 1381-9, PMID 21562233.
Related:
“Night Eating: A Triple Weight-Whammy”
Next post:
Think outside the diet to make weight loss last with “The Mindfulness Meal Meditation” posted on our NewView blog.
You’ll get plenty of clarity about what’s true and useful—or not—by keeping up with nutritionist Deborah Kesten, MPH, and research scientist Larry Scherwitz, PhD, the writers of this post, by liking them on Facebook, following them on Twitter, or sending us an email.
Comments:
What are your thoughts about “The Weight Loss Wonder of When You Eat?” Tell us about them in the Comments section below.
