It's almost February, and with luck and willpower, maybe you're still sticking with that New Year's diet resolution. Or maybe you're still gearing up to start.
But although the right diet may help you gain a svelte figure, the wrong one might be a disaster for your skin.
We asked an A team of skin experts for their opinions about some popular weight-loss regimens. They included celebrity dermatologists Jessica Wu, whose new book, "Feed Your Face," hits shelves Feb. 1; Howard Murad, author of "The Water Secret: The Cellular Breakthrough to Look and Feel 10 Years Younger"; and David Colbert, author of "The High School Reunion Diet," who also has a degree in internal medicine and has been a consultant for Chanel. We also asked dietitian Linda Illingworth, director of nutrition at the famed health spa Cal-A-Vie, to weigh in on fad dieting and share tips on achieving beautiful, glowing skin even as you work toward a slimmer, healthier body.
Super low calorie diets
The human body is designed to function on a varied diet, Murad says, and it's engineered to make the most of a broad mix of vegetables, fruits, grains, proteins and fats to obtain vitamins, antioxidants, glucosamine, essential amino acids and minerals. Fad diets or those too low in calories (roughly fewer than 1,400 a day for men and 1,000 per day for women) can deprive the body of this variety of healthful foods, thus depriving it of the raw materials for healthy new cells and critical vitamins that are essential to building and preserving collagen. This can make the skin lose elasticity and sag, "making you look much older than your real age," Murad says. Skin may become extremely dry, lackluster, sallow and prone to infection. Extreme dieting consequences also include broken nails and dull, brittle hair.
"In the long term, extreme dieters can lose their hair completely," Murad says. Very low calorie diets can be so stressful that the body goes into a starvation survival mode, "which oddly enough makes you store fat once you end your restrictions."
The master cleanse
This regimen, purportedly used by celebrities in search of quick weight loss, involves drinking a laxative tea at night, drinking salt water in the morning and then consuming nothing but a concoction of lemon juice, water, maple syrup and cayenne pepper the rest of the day.
The cleanse has many of the same problems associated with other nutrient-restricting diets. And don't be fooled into thinking that the water in liquid-based diets like this one will help your skin by itself.
True, the skin's epidermis (the outer layer of the skin) contains cells that, when plump with water, have a nice cell membrane to keep the water within the cell. The dermis (the layer below the epidermis) is made of water-absorbent collagen, elastic tissue and reticular fibers. With enough collagen in your skin, you have fewer wrinkles. But just drinking a lot of water isn't enough by itself to help, because "water can go right through you," Murad says.
"As we age and have disease, our cell membranes become thinner and thinner and become porous and lose water," Murad says. In addition to drinking water, "we need to also strengthen and repair the cell membranes to keep the water in." This process requires a varied, healthful diet.
"What is amazing is that some extreme dieters develop rashes and acne-like lesions on their skin due to the stress on their system but tell themselves that these symptoms mean that they are purging toxins," Murad says. "Your body does a fine job of purging waste and impurities without the shock of extreme dieting."
As to the saltwater flush that's part of the regimen, Murad warns that salt water can simultaneously dehydrate and cause bloating.
High protein, low carb
"Without adequate carbohydrates, the body breaks down fat for energy," Illingworth says. "This robs the skin of fatty acids necessary to maintain cell structure, moisture and softness."
She adds that the ketones produced as the body burns fat create a more acidic environment in the blood and are toxic in higher concentrations, creating inflammation of the blood vessels that feed and nourish the skin. "This is often seen in the ruddy complexion of alcoholics. Eventually the blood vessels can be seen at the surface of the skin — tiny, red and broken." Also, you may have less energy to exercise, which could deprive the skin of proper blood circulation and make it dull.
Extreme low-fat diets
"These diets make us fatter, first of all," Illingworth says. "Secondly, without adequate fat in the diet, it's very difficult for the body to get the essential fatty acids that become part of the cellular structure of the skin and arteries and make them soft, pliable and moist."
She says that for most people on this kind of diet, carbohydrate consumption increases dramatically, which can lead to higher blood sugar and increase irritation in the arteries. Over time, this irritation damages the blood vessels that bring nourishment to the skin. "Also, glucose will bind with proteins in a process called glycation, making cells stiffer, less pliable and more subject to damage and premature aging," Illingworth says. "This process is considered a rather significant aspect of aging of the skin. High blood sugar is also seen as the culprit in teenage acne … not fats, as once thought."
The junk-food diet
Professor Mark Haub of Kansas State University had a theory: that losing weight is primarily about calorie counting — not nutrition. So, as an experiment, he limited himself to 1,800 calories a day, but for two-thirds of his meals, Haub indulged in Twinkies, Little Debbie cakes, Doritos, Oreos, Kellogg's Corn Pops — well, you get the picture — and indeed lost 27 pounds in two months.
But Illingworth has seen that, over time, if a diet doesn't provide enough fresh vegetables, fruits, whole grains and essential fatty acids, there will be nutrient deficits that affect the body's detoxification systems (the liver, especially). "And this seems to translate to cancers," Illingworth says, adding that research suggests that taking a multivitamin isn't a substitute for healthful eating.
She says that junk foods also keep glucose levels high, which can cause skin-aging inflammation. "Inflammation by sugar, and lack of protective fatty acids, is the problem here," Illingworth says.
Caveman and Mediterranean diets
Illingworth believes that these two diets are relatively the same in content and so they have similar skin effects. She says that the regimen of legumes, vegetables, fruit, whole grains, fish and monounsaturated fats from olive oil and nuts suppresses inflammation and so protects those tiny blood vessels that feed the skin, making it firmer and giving it a glow. (The Sonoma Diet also uses Mediterranean Diet principles, although it is more carbohydrate restrictive in its first phase.)
"These diets support the immune system by providing not only the essential nutrients and low glycemic properties, but with fibers that are prebiotics," Illingworth says. "Prebiotics [mostly soluble fibers found in foods such as garlic, soy and Jerusalem artichoke] are what the probiotic bacteria feed on, and they live in the intestines." Studies show there is a direct correlation to the health of your intestines and the health of your skin, she says. "They are finding that mothers who have good intestinal bacteria or take a probiotic in pregnancy have children who are at less risk for eczema," Illingworth says.
These usually require drinking a vegetable juice blend for three to seven days to detoxify the body, easing in and out of eating solid foods.
"Raw fruits and vegetables are great. I love raw fruits and vegetables," Murad says. But he adds that you have to make sure that the skins of those fruits and vegetables go into the juice because that's where many of the nutrients and antioxidants important to skin health reside. Also, check that your juices don't skimp on collagen-building proteins.
The Cabbage Diet
This regimen is centered on a special cabbage-based soup and allows some fruits and other foods as it goes along. In addition to the pitfalls of any calorie-restrictive diet, if you add a lot of salt to the soup, you open the door to cell dehydration and bloating, Murad says.
This diet is based on the principle that people like to eat, so it recommends low-calorie foods that fill you up without many calories — foods with a high water content such as soups, fruits, vegetables and low-fat dairy products. To get water into your cells, Murad says that the No. 1 thing you can do is consume your water via nutritious foods such as fruits and beans. If a volumetric diet is followed correctly, Murad says, "you're getting the water you need, you're getting roughage and you're getting antioxidants and you're getting bionutrients, as well."
Eat for glowing skin
Whether you are trying to lose weight or not, what you consume is important to skin health.
"Skin care products alone aren't enough to preserve or improve your looks over time," Wu says. "It's just as important to feed your skin what it needs to build healthy collagen and elastic tissue, and to fight the effects of falling estrogen levels that starts to happen in your 30s and beyond."
Her prescription for beautiful skin includes omega-3 fatty acids (found in salmon, trout, sardines, walnuts and flaxseed). "They can improve your skin's elasticity so it bounces back into place after smiling or squinting, keep skin cells flexible and prevent your skin from drying out," Wu says.
Red wine is high in polyphenol antioxidants, which can help fight sun damage, she says. Eat plenty of protein, since collagen and elastic tissue, which keep your skin firm and resilient, are proteins.
Eat green and yellow vegetables. "Studies show that people who eat lots of green and yellow vegetables tend to have fewer wrinkles, especially around the eyes, than those who don't," Wu says. Also eat cooked tomatoes. Studies have shown they help improve fine lines, aid in skin hydration, improve elasticity and fight sun damage.
And avoid sugar, whether from glucose or fructose. Face-friendly, low-fructose fruit choices include strawberries, blueberries, blackberries and oranges. Colbert also recommends Greek yogurt for its anti-inflammatory and anti-aging effect.
Just cut your calories a little, eat a varied diet, exercise more and you should be able to lose weight beautifully.