Why? Because our bodies require a consistent balance of healthy macro-nutrients (protein, fat, and carbohydrates), as well as micronutrients (vitamins, minerals, antioxidants, phytochemicals), plus adequate phytonutrients, enzymes, fiber, water, and so on in order to function optimally.
When we are missing these elements, our energy levels drop, our hormones and neurotransmitters get imbalanced, and our metabolism stops working efficiently. Our vitality suffers, and our bodies don’t regulate much of anything (including our weight and body composition) as they are designed to.
The health of our metabolism — the machinery that dictates how we burn fat and produce muscle — requires whole, “real” foods and the complex, synergistic blend of nutrients they contain in order to function properly.
This is why replacing whole foods with “diet” fare (or foods selected exclusively on the basis of their low-calorie, low-carb, high-protein, or low-fat characteristics) generally works against long-term weight loss.
A diverse, whole-foods diet will also naturally offer a relatively low glycemic load (GL) and a high phytonutrient index (PI).
A low-GL meal slows the rate at which carbs turn to sugar in the bloodstream. And this slow burn allows your body to digest sugars, says Hyman, “without triggering the metabolic signals that promote hunger and weight gain.”
Phytonutrients, meanwhile, are powerful healing agents and metabolic regulators necessary to the body. (For more on phytonutrients, see “Full-Spectrum Eating”.)
To make the most of the calories you ingest, emphasize foods with a low GL and high PI, including vegetables, fruits, beans, nuts, seeds, olive oil, whole-kernel grains, teas, herbs, and spices. Say no to diet plans that emphasize caloric quantity over nutrient quality.
While calorie-restricted diets can and do trigger temporary weight loss, they also tend to have some unfortunate long-term consequences. Among the most maddening: They can put the body into a hunger-creating “fat-conservation” mode.
When you take in fewer calories than are necessary to fuel your resting metabolic rate (the base amount of caloric energy your body requires at rest), your body simply compensates by reducing your metabolic rate.
Goodbye, caloric burn. Hello, weight rebound.
“Your body thinks it’s starving to death,” explains Hyman. As a result, it not only cuts back on the energy you need to be active and alert, it also “sets off chemical processes inside you that trigger cravings and compel you to eat more.”
The net result is a lack of appetite regulation, a reduction in physical activity, and an increase in fat storage.
You can get a rough estimate of your resting metabolic rate, says Hyman, by multiplying your weight in pounds by 10: If you weigh 150 pounds, for example, your resting metabolic rate would be approximately 1,500 calories per day.
“If you eat less than that amount, your body will instantly perceive danger and turn on the alarm system that protects you from starvation and slows your metabolism,” says Hyman.
The deprivation diet — characterized by “just-until-I-lose-this-weight” thinking — is another enemy of weight loss. It causes us to alternate between extremes of “on diet” and “off diet” behavior.
“Eventually you’re going to stop consuming less, and when you stop, you will gain back more fat than you lost,” says Jonathan Bailor, author of the New York Times bestseller The Calorie Myth. “Because when you go back to eating your previous diet, you will be putting that high-calorie, low-quality food into a destroyed metabolic system.”
Overall, these experts agree, dieting sets us up to have an unhealthy relationship with food that can turn weight management into a miserable, lifelong struggle.
A better approach is to decide to eat healthy for life. Enjoy delicious, whole, high-quality foods in ways that nurture your body for the long haul.
The key is understanding the differences between bad fats (notably the trans fats and unstable or rancid fats often found in processed foods) and good fats (namely those found in fresh, whole foods like nuts, seeds, fish, and wild or pasture-fed meats).
Biochemist and nutritionist Mary Enig, PhD, and nutrition researcher Sally Fallon, authors of Eat Fat, Lose Fat, specifically advise eating small to moderate amounts of saturated fat, the kind found in real butter, cream, grassfed meats, and virgin coconut oil.
Your body needs not only omega-3 fats, they say, but also some plant-based omega-6s and a certain amount of the much-maligned saturated fat in order to nourish your brain, heart, nerves, hormones, and cell structures.
Fail to get these fats, assert Enig and Fallon, and both your health and weight-loss efforts will suffer for it: “Your energy drops, your nerves don’t fire efficiently, glands malfunction, and your hormones and metabolism head south,” they explain. “With cells weakened from lack of necessary nutrition, weight loss is an uphill battle.”
Eating a moderate amount of the good fats found in whole foods not only helps our bodies stay healthy and vibrant, it also delivers the benefit of controlling blood-sugar levels and appetite, both of which have a direct impact on successful weight loss and maintenance.
Most nutrition experts suggest getting between 20 and 35 percent of your daily calories from fat, and many now advocate for more. Be vigilant about including fat in the form of nutritious whole foods (think avocados, nuts, fish), healthy oils (cold-pressed olive, seed, nut), and some appetite-satisfying saturated-fat indulgences (real butter and cream, grassfed meats, coconut).
Being fit gives you a distinct metabolic advantage at a cellular level. Fit people have a greater number of mitochondria — the energy factories within our cells. Mitochondria handle the aerobic oxidation of fatty acids (fat burning!) that occurs even when we’re at rest. Thus, increasing the number of mitochondria through exercise helps raise our metabolism so we burn more calories — not only with every workout session, but also when we’re not exercising at all.
Performed at the proper intensities and intervals, both strength and cardio training can help build lean muscle mass, increase mitochondrial function, and, in turn, increase metabolic rate.
Fitness-focused exercise also improves your strength and endurance, which makes activities of all kinds easier, and thus encourages you to be more active overall. And, since regular exercise also improves your energy level, confidence, emotional outlook, and self-esteem, it can help you get through weight-loss plateaus, when you’re not seeing the inches melt off as quickly as you’d like.