As a registered dietitian, I don't believe that losing weight fast is the healthiest approach. It often backfires, which leads to regaining all (or more) of the pounds shed, and it usually results in shedding only water weight, rather than body fat.
That said, I've counseled hundreds of people throughout the years, and some need to see quick results in order to feel confident and successful, which allows them to build the motivation and momentum needed to ease into long-term lifestyle changes. The latter is the ultimate goal, and the best way to achieve lasting weight-loss results.
But if you're initially motivated to drop a few pounds fast, here's a primer on what you should know, including the safest approaches, and who should definitely not go down the quick fix path.
Losing weight fast: what research shows
Some research indicates that the rate of weight loss doesn't necessarily dictate results down the road. One study, published in the journal The Lancet Diabetes & Endocrinology, enrolled over 200 men and women with high BMIs. During the first phase, participants were assigned to either a 12-week rapid weight loss plan, or a 36-week gradual weight loss program. Both approaches were designed to reduce weight by 15%. Those who lost 12.5% or more weight during phase one were placed into a phase two weight maintenance plan for 144 weeks. At the end of the study, both the subjects who lost weight gradually and those in the rapid weight loss group had regained most of their lost weight.
While this wasn't a good outcome in terms of weight management, researchers say the results indicate that the rate of weight did not affect the proportion of weight regained. In other words, the findings are not consistent with the belief that weight lost quickly is regained more rapidly. However, this study does support a result I've seen over and over in my practice, which is that keeping weight off requires making changes you can sustain long term.
Eating less of these foods might help
Most weight loss tactics focus on what to cut out. For quick results, you'll see the greatest impact when you ditch the usual suspects: processed foods, including fast food; sugary foods, like candy and sweet drinks; products made with refined white flour and sugar, including baked goods; and items high in sodium, such as frozen dinners, pizza, and canned soup.
These foods can trigger water retention and bloating, which can affect your weight on the scale and how your clothes fit. They also generally pack a more concentrated amount of calories or carbs per serving, which can create surpluses that interfere with weight loss. And these foods are typically stripped of nutrients and fiber. The latter delays the return of hunger and helps regulate blood sugar and insulin levels, which are tied to weight management.
If you clear your kitchen and grocery cart of these foods, just be sure to replace them with nutrient-rich whole foods (see more below). Eating too little can leave you feeling hungry, irritable, fatigued, and constipated, which can trigger a binge. And don't swap them with "diet" foods made with artificial sweeteners or sugar alcohols. These faux sugars can stoke a sweet tooth, throw off appetite regulation, and potentially cause bloating. What you replace these foods with is just as important as nixing them.
Eating more of these foods is also smart
Non-starchy veggies are at the top of the list of foods to incorporate into every meal. Most provide 25 calories or less per cup (about the size of a tennis ball) and are low in carbs while packing filling fiber and fluid as well as many nutrients. Aim for about five cups per day, such as one cup at breakfast, two at lunch, and two at dinner.
This can include greens and raw vegetables, or sautéed, oven roasted, or grilled veggies. Try to mix up the colors and types to take in a broader array of nutrients and antioxidants. Blend spinach or kale into a smoothie at breakfast, or sauté veggies like tomatoes, mushrooms, onions, and greens with eggs. Make an entrée salad or Buddha bowl your go-to lunch, with a base of greens and veggies the size of two handfuls. Opt for cooked veggies at dinner, in a dish like a veg-packed stir-fry. Or cover half of your dinner plate with sautéed or oven roasted veggies, such as broccoli, Brussels sprouts, green beans, eggplant, or cauliflower.
Round out your meals with lean proteins, healthy fats, and smaller portions of whole food carbs. Proteins can include plant or animal sources, including pea protein powder in smoothies, lentils and beans, pasture raised eggs, or fish. Healthy fats boost satiety and keep you fuller longer. To get your fill, blend nut butter in a smoothie, serve avocado with eggs, toss salads with extra virgin olive oil vinaigrette, and drizzle pesto over cooked veggies.
Finally, don't omit nutrient-rich, whole-grain carbs like brown rice and quinoa, starchy veggies (including skin-on potatoes and butternut squash), and fresh fruit. To meet your energy needs, include at least one cup fresh/raw or a half cup cooked carbs per meal. Leaving them out can result in lingering hunger or cravings, plus spontaneous snacking that hinders results. In other words, don't fall into the old trap of making meals out of steamed veggies and plain grilled chicken. In addition to feeling miserable, you'll burn out quickly and deprive your body of important nutrients.
What to drink and not drink
You don't have to give up coffee, but do doctor it up with a little unsweetened plant milk, sugar in the raw or maple syrup, and cinnamon, rather than refined sugar or artificial sweeteners and cream or dairy. After a cup or two, switch to water, and aim for 64 ounces spread evenly throughout the day. Make water your only beverage, and if you don't like it plain, flavor it with all natural ingredients like citrus, fresh mint, cucumber, ginger, or bits of in season fruit.
Eliminate alcohol, at least short term. In addition to its calories, alcohol is an appetite stimulant and it lowers inhibitions, so you're more likely to overeat or nibble on foods you wouldn't eat when sober. For a longer-term strategy, limit alcohol to a few occasions per week, and stick with cocktails made with sparkling water rather than regular or diet colas or tonic water.
Who should not attempt quick weight loss
Before you try to lose weight at all, examine your relationship with food. If you have a history of disordered eating, or if previous weight loss attempts have led to feelings of depression, anxiety, anger, loneliness, or other emotions, take a beat. Health includes both physical and emotional well-being, and if a focus on weight loss harms your mental health, it is not a worthy trade. Explore why you feel compelled to lose weight, and seek out support from loved ones who care about you or a mental health professional.
Losing weight fast: bottom line
In my years of working with clients on-on-one, I think I've seen it all, from cleanses and detoxes, to dozens of quickie diets. I've also observed very predictable patterns related to weight loss, including what tends to stick or fizzle out, and the methods that enhance health versus those that deter from it. If you're a good candidate for a weight loss jump start, please consider these two final bits of advice. First, extreme methods don't lead to better results. Second, if you want to keep the pounds you lose off permanently, settle into an eating pattern you can sustain long-term, so you won't wind up taking another wild ride on the unending weight control rollercoaster.
Cynthia Sass, MPH, RD, is Health's contributing nutrition editor, a New York Times best-selling author, and a private practice performance nutritionist who has consulted for five professional sports teams.
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