There is now a way you can boost your metabolism without changing how much you eat. It's true. You can rev up your metabolic engine, feel more satisfied when you eat, burn more calories, and lose more body fat -- all without even changing how MUCH you eat.

Recent studies show how three key changes can help you accomplish your weight loss goals without changing the amount you eat. They are:

1. Meal timing and meal frequency -- In other words, when you eat and how often.

2. Meal composition -– Specifically the role of protein in controlling appetite centers in your brain, increasing caloric burning, and reducing belly fat and weight.

3. Drinking green tea -- Which turns up your fat burning thermostat.

All three of these things have one very important concept in common: thermogenesis -- the creation of heat in your body. When you increase the thermogenesis in your body you literally turn up your metabolic fire.

Thermogenesis has nothing to do with the amount of calories you consume. It's controlled by a number of different interconnected control systems in the body designed to keep us healthy. By optimizing these systems you can turn up your metabolic fire without turning down the foods you love.

Today I will explain how the three key factors outlined above affect thermogenesis and give you a 5-step plan to increase your metabolic fire. Let's start by taking a look at the first thing that increases thermogenesis -- when and how often you eat.

Meal Timing and Frequency

Whether you eat all your day's food at once or in several meals throughout the day shouldn't affect your weight -- it's all about calories in, calories out, right?

No!

In fact, a recent study published in the American Journal of Clinical Nutrition (i) looked at the effects of regular meal frequency on fat burning (your internal thermostat), insulin sensitivity, and cholesterol in healthy obese women. The researchers compared people who ate small, regular, frequent meals (about 6 a day) to people who ate less regular meals a day.

What they found is that those people who had more regular meal patterns showed startling differences. They had increased thermogenesis -- a faster, hotter, metabolism -- from what is called the thermic effect of food (the TEF factor). This TEF factor makes you feel full. It somehow triggers the brain to feel satisfied and reduces your appetite.

When you eat regularly throughout the day, you get a slow, steady burn effect from the food. But when you eat erratically -- by skipping meals, snacking frequently, eating away from home, or eating late -- like so many of us do, your body gets mixed signals.

This irregular eating pattern leads to a lower energy expenditure (EE), or calorie burning, than regular meals. In fact, during the periods that you don't eat, your body's metabolism slows down to conserve energy. And it's not just your weight that can suffer as a result ...

In the same study, the authors found that those who ate irregularly had higher levels of cholesterol and higher levels of insulin, which is the major fat storage hormone. The more insulin that your body makes after meals, the fatter you will be. And, as you know, insulin imbalances can also lead to a host of health problems including insulin resistance and type 2 diabetes.

Meal timing makes a difference, too.

Studies show that eating breakfast (ii) and not eating late (iii) can both lead to reductions in body weight, independent of calories. (For more on this, see Chapter 5 in UltraMetabolism on the Sumo Wrestler Myth).

What's so amazing about all this is that it has nothing to do with the content or type of food you eat. Simply changing when and how often you eat can have dramatic effects on your weight!

But, of course, what you eat makes a difference too ...

Meal Composition

Now let's look at the effect of changing the composition of the meal. What happens if you change the ratio of fat, protein, and carbohydrates, but not the amount of calories you eat?

Recent studies have clearly shown that low-fat diets don't work. End of story. What about low-carb diets?

These do work IF you give up carbs -- the most important source of health-giving compounds in our diet, including fiber, vitamins , minerals, antioxidants, phytonutrients, and more. So weight loss from a low-carb diet comes at high price: poor health!

Low-carb diets also give you constipation, bad breath, hemorrhoids, headaches, and even muscle weakness and pain.

That leaves the question of protein. What happens when you increase the amount of protein in your diet?

Before I go on, let me clarify that when I am talking about increasing protein I mean nuts, seeds, beans, whole grains, omega-3 eggs, wild fish, and lean poultry or other meats. I am by NO means talking about a steak and cheese diet!

That said, protein, it seems, is more thermogenic. It burns hotter than other food sources -- so at the end of the day, you have burned off more calories than you store when you eat more protein. Don't just take my word for it. Science backs this up.

In one study, for example, the participants who got 36 percent of their daily calories from protein burned 71 more calories a day than those who ate low-protein diets (15 percent of calories). (iv) This may not seem like much -- but over a year, it's equivalent to an extra 7.4 pounds of weight loss!

This works because amino acids, the building blocks that form protein, send messages to areas in the brain that signal you are full. This is called the mTOR signaling pathway. (v) But protein has even more benefits ...

Eating good quality protein not only helps you lose weight, but lose it in the right places - your hips and belly. A higher protein diet can help you lower your waist circumference, waist-to-hip ratio (one of the most important measurements in your body which predicts heart disease, cancer, and death better than almost anything), and intra-abdominal adipose tissue (otherwise known as belly fat)!

There are just a few caveats ...

People with kidney failure have to be cautious with increasing their protein intake. And those with concerns about osteoporosis should focus on plant sources of protein (like nuts, seeds, beans, and whole grains), because the high acid content of animal protein may cause bone loss.

We’ve now covered meal timing, frequency, and composition. Next let’s look at what you drink.

Green Tea

Tea is the most widely consumed beverage in the world -- and I'm not talking about Lipton's tea here, which is the bottom of the barrel in terms of quality. I am talking about real, brewed green tea which is part of a fantastic class of compounds called polyphenols -- powerful plant chemicals or phytonutrients that interact with human biology to keep us healthy.

The polyphenols green tea contains are called catechins, and this group of chemicals has such wide effects that it would be impossible to discuss them all in one blog. So for now, let's look at just their metabolic effects.

The same issue of the American Journal of Clinical Nutrition I mentioned previously also reported on the effects of green tea on metabolism. (vi) Researchers specifically focused on the effects of catechins on metabolism in this double-blind, controlled study and found they were two-fold.

First catechins increased thermogenesis, or calorie burning. People who drank 690 milligrams of catechins in the form of green tea daily for 12 weeks had lower body weight, body mass index, waist circumference, total body fat, and subcutaneous body fat. That's WITHOUT changing their calorie intake.

The second effect was green tea's antioxidant properties. Not only did the green tea and catechins increase calorie burning, but they prevented the damaging effects of free radicals on metabolism by reducing oxidized or rancid fats. Other studies show how rancid fats and oxidation may interfere with metabolism.

To sum up, this research shows that green tea can affect weight loss in two ways -- by increasing thermogenesis and by reducing the damaging effects of oxidative stress on metabolism.

So what can you do to incorporate these research findings into your life, lose weight, and increase your metabolism without changing the calorie content of your diet? Just follow these simple steps.

5 Steps to Lose Weight Without Changing What You Eat

1. Start the day right. Eat breakfast every day, and eat protein for breakfast every day. Try omega-3 eggs, nut butters on whole grain bread, and protein shakes.

2. Boost your protein intake. Have some protein with every meal.

3. Stay regular. Eat regular meals every day. That's breakfast, lunch, dinner, and one or two snacks.

4. Don't go to bed too full. Finish eating 2 to 3 hours before bed.

5. Make a cup of tea. Drink 1 to 2 cups of good quality green tea every day. Steep one tea bag for 5 minutes in hot water and enjoy!

Follow these steps and you will not only lose weight without changing what you eat, but you will be well on your way to lifelong vibrant health.

Now I'd like to hear from you ...

What happens to you if you skip meals?

Have you noticed that eating carbs for breakfast increases your appetite throughout the day, or that having that omelet in the morning is more satisfying?

Have you experimented with low carb or low fat diets? Share your experience with us.

Please let me know your thoughts by adding a comment below.

To your good health,

Mark Hyman, M.D.

References

(i) Farshchi HR, Taylor MA, Macdonald IA. Beneficial metabolic effects of regular meal frequency on dietary thermogenesis, insulin sensitivity, and fasting lipid profiles in healthy obese women. Am J Clin Nutr. 2005 Jan;81(1):16-24.

(ii) de Castro JM. The time of day of food intake influences overall intake in humans. J Nutr. 2004 Jan;134(1):104-11.

(iii) Keim NL, Van Loan MD, Horn WF, Barbieri TF, Mayclin PL. Weight loss is greater with consumption of large morning meals and fat-free mass is preserved with large evening meals in women on a controlled weight reduction regimen. J Nutr. 1997 Jan;127(1):75-82.

(iv) Whitehead JM, McNeill G, Smith JS. The effect of protein intake on 24-h energy expenditure during energy restriction. Int J Obes Relat Metab Disord. 1996 Aug;20(8):727-32

(v) Cota D, Proulx K, Smith KA, Kozma SC, Thomas G, Woods SC, Seeley RJ. Hypothalamic mTOR signaling regulates food intake. Science. 2006 May 12;312(5775):927-30.

(vi) Nagao T, Komine Y, Soga S, Meguro S, Hase T, Tanaka Y, Tokimitsu I Ingestion of a tea rich in catechins leads to a reduction in body fat and malondialdehyde-modified LDL in men. Am J Clin Nutr. 2005 Jan;81(1):122-9.