Filed under: Weight loss
Intermittent fasting has become a popular strategy for weight loss. “Fasting” can mean different things—from fasting as much as 16 hours per day to skipping or restricting caloric intake (for example, to less than 500–600 calories) one or two days a week. Fasting programs may make promises to their followers to lose weight and improve health, but are they safe and effective?
The health benefits claimed for intermittent fasting have mostly come from studies with animals. A few small studies with humans have shown intermittent fasting—eating as usual five days a week and eating 25% less two days per week—may be useful for weight loss. Because these studies were short term, however, the long-term safety and effectiveness of intermittent fasting are unknown.
In addition, it is unclear if intermittent fasting is more effective for weight loss than just eating less on a daily basis. Intermittent fasting could lead to overeating on non-fasting days, and even advocates of intermittent fasting point out that the key to weight-loss success is not to overeat on “normal” eating days.
Eating too few calories over time can result in low levels of vitamins, minerals, or other nutrients, and even the loss of muscle mass. And intermittent fasting can be dangerous for people with medical conditions such as pregnancy, diabetes, or eating disorders.
Common side effects of fasting include lack of energy, headaches, feeling cold, and constipation. Fasting can cause low blood sugar if you aren’t getting enough fuel to your brain, reducing your ability to concentrate and focus and affecting your sleep cycle and mood. These effects can interfere with your body’s ability to perform optimally.
Athletes who fast during Ramadan—a holy month when Muslims are expected to fast daily (no food or water) from pre-dawn prayer to post-sunset—provide some insights into the effects of fasting on performance. The limited intake of carbohydrates, protein, and fluid during fasting days sometimes affects their bodies’ ability to recover from exercise. Some found that their cognitive performance suffered as well due to the effects of even mild dehydration and inadequate carbohydrate intake. Exercise that is both physically and mentally challenging and long-lasting could have even greater negative effects.
Intermittent fasting may be unrealistic for long-term use. Reducing your overall caloric intake and a regular exercise program are the best combination for weight loss.
Weight-loss (diet) prescription medications are generally not permitted, but it’s important to check your service’s policy for specific conditions that may exist. Read this OPSS FAQ to find out more details, including links to specific policies. Also, be sure to check the OPSS site often, as we add answers to other questions about ingredients in performance-enhancing and bodybuilding supplements and how to choose supplements safely.
If you have a question about a particular dietary supplement ingredient or product, please use our “Ask the Expert” button located on the OPSS home page.
Phentermine, a prescription drug used for weight loss, is similar to amphetamine. So, will it cause you to pop positive on your military drug test? Is it ok to use as long as you have a prescription? Read the OPSS FAQ to find out answers to these questions.
OPSS has other FAQs to help answer questions about the safe use of dietary supplements. And the OPSS High-Risk Supplement List will be available soon, so check the OPSS homepage often for up-to-date information.
Dietary supplements with conjugated linoleic acid (CLA) are being marketed to help with weight loss. What is CLA and can it really help you lose weight? Read HPRC’s new Operation Supplement Safety (OPSS) FAQ about CLA to find out.
While you’re there, check out our other OPSS FAQs. Still can’t find the answer you’re looking for? You can visit the Natural Medicines Comprehensive Database or use our “Ask the Expert” button located on the OPSS home page.
Garcinia cambogia is being used as a dietary supplement ingredient in some products marketed for weight loss. What is it? And is it effective? Read this Operation Supplement Safety (OPSS) FAQ about Garcinia cambogia to find out. Be sure to check back often, as we add answers to other questions about ingredients in performance and weight-loss supplements and how to choose supplements safely.
If you have more questions about a particular dietary supplement ingredient or product, you can visit the Natural Medicines Comprehensive Database or use our “Ask the Expert” button located on the OPSS home page.
Two versions of OxyELITE Pro have been removed from the market in the past year. Read the Operation Supplement Safety (OPSS) FAQ to find out why, and to get more information from the Food and Drug Administration (FDA). Also, be sure to check back often, as we add answers to other questions about ingredients in performance-enhancing and weight-loss supplements and how to choose supplements safely.
If you have more questions about a particular dietary supplement ingredient or product, please use our “Ask the Expert” button located on the OPSS home page.
There’s an old adage you may have heard: “Eat after eight, put on weight.” And maybe you’ve experienced it first-hand: You noticed that eating those late night pizzas and ice cream really packed on the pounds. But was your weight gain due to timing or just the high calorie counts? According to research in the field of circadian rhythms (CRs)—the 24-hour cycle of your body’s biological, hormonal, and behavioral patterns—it seems that when you eat could be just as important to weight gain as what you eat.
Deep within your brain sits a small cluster of nerve cells—a “master clock” of sorts—that’s responsible for orchestrating your CRs. Each biological system in your body works on a different CR schedule, and the master clock keeps all the schedules in sync. For example, CRs influence your body’s production of the hormones that regulate hunger, as well as how your body uses and stores fats and sugar, ultimately influencing your body weight, performance, and overall health. Other hormones, such as the ones that tell you when you’re full, are switched on or off according to a variety of inputs.
The two greatest influences on how well your master clock is able to keep things in sync are light and food. Light tells your brain how much sleep you get (think: eyes closed, less light). Food (smell, taste, and consumption) tells your body to produce a myriad of chemicals. As a result, staying up late at night, working shifts, and eating at all hours of the day and night—whether voluntarily or due to the demands of overseas deployments, training demands, shift-work schedules, and even parenthood—can play havoc with your circadian rhythms.
In an interesting twist, not only do CRs influence hunger and body weight, but excess body fat and/or a high-fat diet may disrupt CRs. This can lead to further weight gain, culminating in a collection of health problems known as “metabolic syndrome.” In the U.S., regular loss of sleep closely parallels the occurrence of metabolic syndrome. In addition, researchers have found that people who sleep less or have poor-quality sleep are more likely to become obese.
What to do? Make a conscious effort to “normalize” your daily routines as much as possible to maintain regular mealtimes. Whether you choose to eat three regular-sized meals or four to six smaller meals a day, space them out through the daylight hours to take advantage of your body’s natural rhythms. Here are some suggestions to avoid eating late at night:
- Try to eat a balanced dinner at least two hours before you go to bed, and take a walk afterwards when possible.
- Sip on soothing herbal tea or flavored water (without sugar).
- Be aware that watching TV (especially food-related ads) can trigger your desire to eat.
- Sometimes it can help to create new nighttime rituals that don’t involve eating, such as light stretching or yoga, taking a warm bath, listening to soothing music, or reading (or listening to) a book.
But if you find yourself up late at night—whether it’s due to a hard day at work, regular shiftwork, or temporary shifts due to jet lag or an infant’s night feedings—resist the urge to snack out of boredom or to “keep your energy up.” Shift workers should pack or purchase a healthy meal to eat during their work hours—one that includes lean protein and complex carbohydrates such as whole grains, fruits, and vegetables. Eat early in the shift if possible, so you’ll have the energy you need to think and move efficiently. Travelers and parents should look for healthy snacks that follow a similar pattern. And try to limit coffee, tea, and other sources of caffeine to just two to four servings a day.
Of course, eating is just one half of the CR equation. Getting enough sleep is important too, so read HPRC’s overview for great tips on how Warfighters can improve their sleep.
Operation Supplement Safety (OPSS) has added even more questions and answers to its FAQs section on HPRC’s website. Be sure to check back often as we add more answers to questions about supplement ingredients, performance and dietary supplements, weight loss and supplements, and choosing supplements safely. Didn’t find what you were looking for? Use our Ask the Expert button located on the OPSS home page.
You’re watching what you eat. You’re exercising regularly. You’re doing everything right. But for some reason, your weight-loss goal is just out of reach. It seems those “last 10 pounds” are often the hardest ones to shake! Fortunately, with continued effort and persistence, you likely can achieve your weight-loss goals.
If you haven’t done so already, be sure to speak with your healthcare provider or a registered dietitian to make sure the goals you’ve set for yourself are realistic, healthy, and sustainable. After that, it’s time to get to work.
Go back to square one. That is, make sure you’re as careful about what you choose to eat now as when you first started on your weight-loss journey. Sometimes we lapse into old habits over time and start “allowing” unhealthy choices to creep back into our diet patterns. Keeping a food diary will help you keep track of what you’re really eating. And don’t forget to watch your portion sizes.
Be a weekend warrior. Many people find it harder to make healthy choices on the weekend—tailgate parties, family celebrations, and road trips all offer opportunities to “slip.” But eating healthy is a full-time job, so it’s important to plan ahead: Take a low-fat dish that you’ve prepared and choose restaurants where you know you’ll have healthy options available.
Stand up for yourself. Literally. Standing, rather than sitting, can burn as many as 200 to 300 calories per day and can help prevent many types of disease. Find as many opportunities in your day to stand, walk, and move as much as you can. Check out HPRC’s blog about “sitting disease” for more information about the risks of sitting too much.
Shake things up. Varying the type and intensity of your exercise is a great way to challenge yourself and prevent boredom—and can make a big difference toward achieving your goals.
Whatever you do, don’t give up. Achieving and maintaining a healthy weight is important not only in the short term (for your performance as well as your career) but also in the long term, reducing your risk of many diseases including diabetes, heart disease, and certain types of cancer.
Since we first posted our list of DMAA-containing dietary supplement products in December 2011, and especially since FDA’s announcement in April 2013, the number of products being manufactured with this ingredient has continued to decline. Our search does still occasionally turn up products with DMAA that were not on our previous lists: just six new products have been added since our last update in April 2013. Despite these additions, this update shows that about 80 dietary supplement products are apparently still being manufactured with DMAA, but note that many are by non-U.S. sources. Over the lifetime of this list 125 products have been discontinued or reformulated to exclude DMAA, including some of the most well-known ones. To the best of our knowledge and searching, 68 of these no longer appear for sale, even from distributor stock. You'll find our updated list of products containing DMAA here.