Tag Archives: nutrition

Not sure where to begin to improve your health? A guide to taking the first step

If you are thinking about losing weight, becoming more active, or quitting smoking you are not alone. These are three of the most common health-related New Year’s resolutions. Considering that two-thirds of American adults are overweight, about half don’t meet minimum recommendations for physical activity, and one in five smoke, there are many people who need to change more than one of these behaviors.

Quitting smoking and changing eating and exercise habits to lose weight or improve fitness are among the most difficult behavior changes to make, especially at the same time. Some people focus on one change to begin with.

Obviously, changing all three of these behaviors is ideal, but if you are only willing to change one, which should you take on first to have the biggest impact on your overall health? This is the topic of my Health & Fitness column in the Aiken Standard this week.

You might think that quitting smoking would be the most important change to make initially. Smoking is the primary cause of lung cancer and other respiratory diseases such as emphysema and chronic bronchitis. Smoking also increases the risk of most other cancers and is a major contributor to heart attacks and strokes. Quitting smoking greatly reduces these risks with beneficial changes that begin within days of quitting. Despite this, if you only want to change one behavior, smoking isn’t the place to start.

Being overweight is a leading cause of diabetes, high blood pressure, heart disease, and some cancers. If you are overweight, losing just 10% of your body weight (20 lbs. for a 200 lb. person) can significantly reduce the severity of these conditions. Maintaining a healthy body weight can prevent many of these health problems. However, losing weight is not the first change you should make.

It turns out that becoming physically active is the most important change you can make to improve your overall health. Decades of research show that regular physical activity reduces the risk of most chronic diseases including diabetes, heart disease, and some cancers and can extend the lifespan by up to five years. In fact, the health risks of inactivity are equal to or greater than that of obesity or smoking. Regular activity also improves muscular strength, aerobic fitness, bone density, cognitive function, and memory. There is no other single intervention—drugs included—that has as many health benefits.

Research also shows that the negative health effects of being overweight and obesity are, in part, caused by inactivity and poor fitness. If you are overweight but physically fit, your risk of death is lower than if you are at a “healthy” weight but unfit. Regular exercise can reduce the risk of diabetes in people who are overweight, whether they lose weight or not. Furthermore, studies of “successful losers” show that daily exercise is a requirement for long-term weight loss, so becoming active now can help you lose weight later.

You should change all three of these behaviors to achieve optimal health. But if you are looking for an initial step that will have the biggest impact, start by becoming more active. A good initial goal is to reduce the time you spend being sedentary (sitting) and to get a minimum of 30 minutes of moderate-intensity activity, such as a brisk walk, each day. You can get greater benefits by participating in more intense exercise, including strength training, three or more days per week. And once you have established a routine of regular activity you will be ready to make other health changes.

Take a lesson in healthy eating from your turkey this Thanksgiving.

My Health & Fitness column in the Aiken Standard this week is about Thanksgiving dinner. With all the talk about how to make it a “healthier” meal by replacing traditional dishes and modifying recipes, I think we may be missing an important lesson in healthy eating.


This is Thanksgiving week, and people throughout the country are planning a feast including traditional dishes and family favorites. Even though many of these are not the healthiest choices, they make an appearance on the dinner table each year. Combined with the common occurrence of over-indulging, Thanksgiving dinner can represent a day of poor nutrition choices.

In an effort to make Thanksgiving dinner healthier, recommendations for modifying or replacing traditional dishes are a common theme in magazines, on the morning TV shows, and on the web. While these suggestions are meant to be helpful, I’m not sure they actually serve to make a significant impact on health.

After all, Thanksgiving is one day, and if there was ever a day to give yourself license to indulge, this is it! Of course, trying new foods and cooking techniques is always good, but the impact of replacing the butter in your mashed potatoes with fat-free sour cream or taking the marshmallow topping off Granny’s famous sweet potato dish isn’t realistically going to make you any healthier in the long run.

The truth is that if you eat a healthy diet every day, or even most days, and you have an active lifestyle you can get away with a day—or weekend—of overeating. (Obviously, you should always follow dietary restrictions for any medical conditions you have.) The problem comes when Thanksgiving dinner is yet another unhealthy meal in addition to the others that week or month.

Some of these recommendations are worth trying, for sure. Making an alternative to a traditional dish can get your family to try new foods they might not otherwise consider. And cooking using different ingredients or techniques on Thanksgiving can give you ideas for other meals, too.

However, focusing on modifying your Thanksgiving dinner may distract you from appreciating the greatest potential health benefit of this meal. Given the current confusion about how much and what type of carbohydrates and fats we should eat, there is an increased push to get us to eat less processed food and more real food.

For many of us, Thanksgiving dinner is one of the only times we cook and eat real food. A real turkey, vegetables, and home-made dessert are a huge improvement over the processed foods most of us eat on a daily basis. While we eat turkey at other times, it is almost always in a processed form such as ground turkey or deli meat, which frequently includes other additives. Cooking and eating a whole turkey is, for most families, relatively rare. So is eating a meal that doesn’t come from a restaurant or is heated in a microwave.

Additionally, Thanksgiving dinner is shared simultaneously around a common table (and maybe a kids’ table, too). All too often, meals are consumed away from the family table, frequently at different times. The benefits of eating together as a family are well-known, and can impact nutrition, psychological well-being, and health in general. Maybe Thanksgiving dinner isn’t about the food as much as it is the company. Why not make this a habit at other meals?

This week, let’s all give thanks for family, friends, and a shared meal. Let’s also take a lesson from the day and try to prepare and eat more real food as a family. This may be the biggest benefit of Thanksgiving. That, and a second serving of pumpkin pie!

Chill out! Why less stress is essential for good health.

Chronic stress can have serious emotional, psychological, and physiological effects that lead to or exacerbate many health problems. While it is impossible to avoid all stress in life, minimizing stressors and managing the way you respond to stress can have important benefits. Regular exercise, including yoga, managing time better, and getting enough sleep, can help with minimizing your feelings of stress as well as the effects it has on your body.

The importance of stress management and getting enough sleep is the topic of my Health & Fitness column in the Aiken Standard this week.


Chronic stress can have serious emotional, psychological, and physiological effects that lead to or exacerbate many health problems. In fact, the negative health effects of chronic stress are similar to those of eating a poor diet or not getting enough physical activity. That said, managing stress, including getting enough sleep, is often overlooked as a key component of good health.

The word “stress” is typically used to indicate both the feeling of being “under a lot of stress” as well as the things that cause that feeling. The events and situations that cause stress are properly called stressors, which lead to a stress response that includes consequences we feel as well as physiological changes we may not notice.

The immediate effect of a stressor is called the “fight or flight” response since it prepares the body to deal with a dangerous situation. A classic example of this is a caveman who encounters a saber-tooth tiger, clearly a stress-inducing event.

The sympathetic nervous system is immediately activated, which raises heart rate and blood pressure to pump more blood to the muscles. Additionally, stored fat and carbohydrate fuels are broken down as fuel for the muscles. The adrenal glands release catecholamines (adrenaline) and cortisol (the stress hormone) to prolong and enhance this effect. This coordinated response makes sure the caveman’s body is ready for action. After the danger passes, everything returns to normal.

This physiological response is appropriate for major events like saber-tooth tiger encounters, but not for less perilous stressors like being stuck in traffic, pressure at work and home, or other personal and family issues. But the body responds with the same increase blood pressure and hormones to them all. Unlike a rare saber-tooth encounter, these stressors tend to occur on a daily basis, leading to continuous stress response.

The increase in hormones can lead to high blood pressure, obesity, type 2 diabetes, and other chronic diseases. This is partly due to elevated levels of cortisol, a hormone that plays a role in storing fat and increasing appetite. While elevated cortisol during exercise (including running away from a saber-tooth tiger) is normal, chronic overproduction can have negative effects.

While it is impossible to avoid all stress in life, minimizing stressors and managing the way you respond to stress can have important benefits. To the extent that it is possible, avoiding stressful situations through better time management, setting realistic expectations for ourselves and with others, and learning to say “no” are common recommendations.

Learning how to deal with stressors to avoid the negative effects of stress is also important. Techniques that can be implemented in the heat of a stressful moment include taking a break from the situation, listening to calming music, and progressive relaxation. Even taking a deep breath can help.

Exercise has long been recognized as beneficial for reducing stress and the long-term effects of stress on your health. This includes doing something active during a stressful situation and exercising regularly to improve the way your body responds to stress. While all forms of exercise seem to work, much research and practice has focused on specific types of exercise including yoga and Tai Chi.

Other effective strategies traditionally include meditation and relaxation exercises. More and more research shows that getting enough sleep is also critical for reducing stress and the impact it has on your health. Eating a healthy diet can reduce the effects of stress as well.

The bottom line is that a healthy lifestyle includes stress management as well as a good diet and regular activity. Since all three are essential for good health, it would be wise to eat smart, move more, and chill out!

What parents and schools can do to make sure kids are ready to learn

Physical activity and good nutrition have long been recognized as essential for promoting good health in adults and children. More and more research suggests that these health behaviors can have beneficial effects beyond health, including how we perform both physically and mentally. The emphasis here is on children in school, but it applies to adults, too.

Unfortunately, taking time for activity and good nutrition is seen as a luxury or a distraction to learning in most schools. Far from being a distraction, physical activity and healthy eating are prerequisites for learning and academic achievement. In short, these often ignored factors can help make sure children are ready to learn.

Regular physical activity is essential for good health, growth, and physical development, including maintaining a healthy body weight. This last point is important given the epidemic of childhood obesity and related health problems, including “adult” diseases like high blood pressure and type 2 diabetes.

Current recommendations call for all children to get at least 60 minutes of activity per day. This can include activity at school from physical education classes, recess, other classroom activities as well as games, sports, and unstructured play. Unfortunately, most kids don’t get nearly enough activity at school and many aren’t active at home.

Physical activity is also important for academic performance. Research shows that children who participated in an activity program had better executive control, which includes resisting distractions and maintaining focus, improved memory, and doing better switching between tasks. This is particularly relevant for children with ADHD, but the effects can be seen in all kids. These positive changes can maximize class time and lead to improvements in academic achievement, especially math and reading test scores.

Similarly, good nutrition is also essential for health, growth, development, and academic achievement. Eating a good breakfast improves cognitive function, alertness, and academic performance in students of all ages. It should be no surprise, then, that skipping breakfast impairs cognitive function and academic achievement. This is one reason that many schools offer breakfast to start the day or include a healthy mid-morning snack.

The same is true for lunch, too. A good lunch can support learning in the afternoon and gives a chance to teach kids about good nutrition by providing healthy food that, unfortunately, many children may not get at home.

Schools have a unique opportunity to use physical activity and nutrition to promote health, support academic achievement, and teach healthy habits. Since formal nutrition education is missing from most curriculums and PE programs are being reduced or cut completely, schools must be creative to incorporate these essential subjects.

A way around this problem is to make sure children get a chance to move and play, ideally multiple times during the day. This is what recess is for. Teachers can also incorporate activity and nutrition education in the classroom and get away from the idea that kids must be sitting still to learn. As research shows, quite the opposite is true!

Schools are often hesitant to teach about nutrition and activity because it is thought of as a responsibility of parents, not schools. But most parents don’t teach these good habits at home, which affects what happens at school. Despite the obvious benefits, it will probably take years of effort to change this view.

In the meantime, parents can encourage their kids to be active and make smarter food choices at home so they are ready to learn in school.

Celebrate Food Day every day by eating real food

This Friday is Food Day, an annual event that aims to raise awareness about the food we eat and the impact it has on our health, environment, and quality of life. It turns out that many of us don’t know much about our food including where it came from, the method of preparation, and the quality and nutritional value.

As I describe in my Health & Fitness column in the Aiken Standard this week, we are increasingly disconnected from our food, a fact that has implications for our health and the health of the environment.

Our lack of knowledge about the food we eat has been replaced by a heightened awareness about nutrients. In fact, many people follow diets that either emphasize or restrict certain nutrients in order to obtain health benefits. But the research to support the importance of these individual nutrients is often mixed or lacking altogether. Still, as we seek out sources of these nutrients we are led to supplements, such as fish oil, or processed foods with added nutrients, like fiber.

To be sure, fish oil and fiber are good for us. But does that mean that taking a fish oil supplement will have the same health benefits as actually eating fish instead of, say, fried chicken? Or is adding fiber to a chocolate breakfast bar equivalent to getting more fiber from fruits and vegetables? Both research and common sense suggest that the answer is no.

Beyond the individual nutrients, the food we eat has changed. Even the way food gets to our table has changed. Since nearly half of our meals are eaten outside the home, it’s not even “our” table anymore. And when we do eat at home, take-out and prepackaged heat-and-eat meals have become the norm. In fact, the idea of cooking meals from ingredients is so foreign that we have to be reminded about how and why we should do it.

Events like Food Day are an attempt to get us back to the basics of cooking and eating real food. This, of course, is how people ate for years before the obesity and diabetes epidemics we are dealing with now, so eating real food again is a step toward reducing these, and other, health problems.

In addition to the potential health benefits of focusing on food over nutrients, this approach is also good for the environment and the economy. It turns out that eating healthier food promotes sustainable agriculture and can support local farmers. Locally grown produce, which is picked at the peak of freshness, can be more nutritious and have a lower environmental impact than food from factory farms which is often shipped great distances. And most important, food from local farms usually tastes better!

This is the point of Food Day. We should make ourselves aware of where our food comes from and do our best to eat “real food” as opposed to processed and pre-packaged foods that tend to be high in calories, added sugar, salt, and unhealthy fats. When possible, we should buy foods that are grown locally to minimize the environmental impact and support local farmers who live, work, and pay taxes in our area.

It turns out that focusing on food, not nutrients, will have a positive impact on your health, the environment, and quality of life for you and others. And that is why it is called Food Day, not nutrient day. You can learn more about how you can celebrate Food Day every day at www.foodday.org.

Don’t forget about breast cancer prevention!

October is National Breast Cancer Awareness Month and many local and national organizations are promoting breast cancer awareness, sharing information about the disease, and celebrating survivors. This month represents the most visible part of a year-round effort to educate about, screen for, and hopefully cure this devastating disease.

Of course, these are all worthy goals that deserve our attention and support. What is often missing are the steps women—especially young women—can take to reduce their risk for, or even prevent, breast cancer.

Approximately 1 in 8 women will develop breast cancer. The American Cancer Society estimates that around 300,000 new cases of breast cancer are diagnosed and nearly 40,000 women die from this disease each year. Breast cancer can occur in men, but these cases are rare, so the focus is rightfully on women.

Much attention is given to genetic factors that increase the risk of breast cancer. These include certain gene mutations, including BRCA1 and BRCA2, as well as family history. A woman who has a first-degree relative (mother, sister, or daughter) who has had breast cancer has nearly twice the risk of being diagnosed herself.

Considering that most women diagnosed with breast cancer have no family history, it is also important to try to reduce other modifiable risk factors. This involves making health behavior changes that are probably familiar to most people. The good news is that these changes can also reduce the risk of other cancers, cardiovascular disease, and most other chronic diseases.

Avoid tobacco use. While the results of studies of smoking and breast cancer are mixed, a conservative interpretation is that smoking may increase the risk. Smoking increases the risk of other cancers, especially lung cancer, as well as heart attack, stroke, and other lung diseases. Not smoking, or quitting now, is among the best health decisions a woman can make.

Consume alcohol in moderation. Women should limit their alcohol intake to one drink per day. Women who consume more than two drinks per day increase their risk of breast cancer by 20% over women who don’t drink.

Maintain a healthy body weight. Being overweight can increase the risk of breast cancer in post-menopausal women by 30–60%. Excess body fat can alter the levels of estrogen and other hormones. The good news is that losing as little as 10 pounds can reduce this risk.

Be physically active everyday. Regular activity and exercise can lower breast cancer risk by as much as 20%. In addition to helping with weight control, physical activity may lower the level of certain hormones that are associated with breast cancer. The biggest reduction in risk of breast cancer is seen in women who have been active their whole lives, but it is never too late to start.

Eat a healthy diet. The evidence from studies on the effect of diet on breast cancer risk is mixed, and more research is needed. In general, increasing fruit, vegetable, and whole grain intake and reducing red meat is associated with at least some decrease in breast cancer risk. These “healthy” foods are rich in vitamins, minerals, and other nutrients and eating more of these foods may lead to weight loss or prevent weight gain with age.

Every woman has a different breast cancer risk based on her unique family history, biology, and lifestyle. But by making some simple health behavior changes, all women can reduce their risk for, or even prevent, breast cancer and improve their overall health.

 

“Heart” your heart.

Today is World Heart Day, with a focus on encouraging all of us to make heart-healthy choices to reduce cardiovascular disease risk. I thought that sharing some information about the heart, how it works, and how to keep it healthy would be an appropriate way to celebrate. This is also the topic of my Health & Fitness column in the Aiken Standard this week.

Your heart started beating months before you were born and will continue to beat every second or so…until it stops, signaling the end of your life. During your lifetime, your heart will probably beat more than two billion times, or about 100,000 times per day. (more interesting heart facts here)

The major function of the heart is to pump blood to all of your tissues through the arteries and back again through the veins. The heart has four chambers: the left and right atria that receive blood from the veins and the left and right ventricles that pump blood into the arteries. The right ventricle pumps blood to the lungs to pick up oxygen and the left ventricle pumps oxygenated blood out to the rest of the body.

The activity of your heart will vary throughout the day. At rest your heart rate is low, typically around 70 beats per minute. Some athletes have resting heart rates that are much lower, owing to their bigger, stronger hearts.

But when you are active your heart beats faster and more forcefully to eject more blood to the working muscles. During intense exercise, a young person’s heart rate can go above 200 beats per minute and the amount of blood pumped can be five times higher than at rest!

The heart is made up mostly of muscle that functions similarly to the skeletal muscles you use to move your body. But cardiac muscle is different in that it can spontaneously contract when stimulated by a specialized area of the heart called the SA node or pacemaker. And unlike skeletal muscle, the heart is remarkably fatigue-resistant, meaning that it can contract repeatedly without needing a break.

In order to beat continuously, the heart needs a steady supply of oxygen which is delivered through coronary arteries, not from the blood inside the chambers of the heart. Normally, plenty of oxygenated blood gets through. But if the coronary arteries become narrowed through atherosclerosis, the accumulation of plaque in the vessels, blood supply can be limited.

This can lead to reversible symptoms like angina pectoris (chest pain), especially during exertion. If a clot forms in the narrowed vessel, blood flow can be blocked completely causing a myocardial infarction (heart attack). Heart disease can be managed using medications, angioplasty, or bypass surgery, but the best approach is to prevent the problem from occurring in the first place.

Taking care of your heart is one of the most important things you can do for your health. Like other muscles, regular exercise can make your heart larger and stronger to pump blood more effectively. Exercise also lowers your blood pressure and can help reduce your blood cholesterol, further reducing the risk of heart disease.

A diet that is low in salt and unhealthy fats, like trans fats, can help lower blood pressure and cholesterol, slowing the process of atherosclerosis and preventing heart failure, a condition in which the heart muscle becomes weak. Maintaining a healthy body weight and controlling blood glucose are also keys to a healthy heart.

More than anything, though, your heart likes to be active. So celebrate World Heart Day by taking your heart for a walk!

 

Fat still matters

Last week I wrote about some recent research suggesting that low-carbohydrate diets may be better for weight loss that low-fat diets. For many, this study reinforced the notion that traditional recommendations are wrong and that the key to good health is to eliminate carbohydrates from your diet. This couldn’t be further from the truth.

The recent study did show that people lost more weight and experienced beneficial changes in blood lipids when they followed a low-carbohydrate diet compared to those who ate a low-fat diet. However, this does not mean that low-fat diets aren’t effective for weight loss or that they are “unhealthy.”

In fact, low-fat diets have long been used effectively to promote weight loss, reduce heart disease risk, and lead to healthier eating in general. This is supported by the results of hundreds of research studies as well as the practical experience of health professionals and real people. Here are two reasons why fat still matters when it comes to health.

First, reduced-fat diets have been shown to improve blood cholesterol and lower the risk for heart disease. Eating a diet low in fat, especially saturated and trans fat, has been the foundation of nutrition recommendations for decades. The fact is that these diets are effective for weight loss, reducing cholesterol, and otherwise improving heart health.

One famous study demonstrated that following a low-fat diet contributed to a reduction in the severity of atherosclerosis, the narrowing of arteries that leads to many heart attacks. Literally hundreds of other studies have shown similar beneficial results.

This isn’t some magical effect of eating less fat, though. The health benefits are likely due to eating more vegetables, fruits, and whole grains as much as they are to reducing fat intake. The point is that adopting a low-fat diet can lead to better nutrition overall.

Second, reducing fat intake is a good way to reduce calories. This is true because fat contains nine calories per gram, more than twice that of carbohydrates and protein, so cutting fat is an effective way to cut calories. Limiting fat intake also reduces calories indirectly because many high fat foods are also high in sugar and calories (think of most desserts).

It is important to mention that simply reducing fat intake won’t always lead to weight loss; total calories must be lower, too. This is a mistake many make when they reduce fat intake, but increase the amount of calories from other sources, typically carbohydrates. Many low-fat foods are actually relatively high in calories due to added sugar or people tend to eat more of them (the SnackWell Effect).

The effectiveness of low-fat diets for weight loss has been demonstrated in research studies (like this one) and countless weight loss programs. In one notable study, a diet low in fat even led to weight loss in people who weren’t trying to lose weight. And don’t forget that in the recent study about low-carbohydrate diets, the subjects that followed the low-fat diet also lost weight.

For some people, cutting carbohydrates as a way to lose weight is reasonable; for others, reducing fat intake makes sense. For most people, though, doing both to some extent is the best option, but going to extremes is unnecessary.

Eating less added sugar and avoiding foods with added fats (such as French fries) are good recommendations for almost everyone. That said, there is little evidence for the benefit of limiting carbohydrates in the form of whole grains, legumes, vegetables, and fruits or the fat in meat and dairy.

The bottom line is that the quality of food we eat is more important than the specific amounts of the nutrients it contains. Eating low-carbohydrate or low-fat diets can help steer you toward making healthier choices, but so can avoiding processed foods in favor of wholesome, nutrient-dense “real” food.

Good sources of protein for your low-carb diet

Thanks to a recent study and media coverage (including me), low-carbohydrate diets are a popular topic of discussion. For many people, cutting back on carbohydrates is a good way to reduce calories to promote weight loss.

Most low-carbohydrate diets also emphasize protein intake. But finding healthy protein sources is important for promoting weight loss and good health.

This recent discussion about the best protein for optimal weight loss  on the Train Your Body show on RadioMD should help.

The diet wars continue

If you are confused or frustrated by the conflicting claims about whether a low-fat or low-carbohydrate diet is the best, you are forgiven. First we were told that eating a low-fat diet was the best way to lose weight and improve heart health. Then, research suggested that low-carbohydrate diets were better. And back and forth it has gone for years.

During this time, the prevailing recommendations have suggested that a diet low in fat and high in carbohydrates was best. But more and more research has supported the notion that cutting carbohydrates, not fat, would lead to greater weight loss. Although this has been supported by some research, critics pointed out that eating more fat would raise blood cholesterol and other risks for heart disease.

According to a recent study, though, low-carbohydrate diets seem to have benefits for promoting weight loss and improving some indicators of heart health over low-fat diets. But you should hold off on shunning fruits and vegetables in favor of cheeseburgers! Here is a practical interpretation of the research and some common sense recommendations, taken from my Health & Fitness column in the Aiken Standard this week.

The study, published last week in the Annals of Internal Medicine, reported on 150 men and women who either restricted the amount of carbohydrates or fat they ate. After one year, the group that ate a low carbohydrate diet lost over 7 pounds more than the subjects on the low-fat diet. Additionally, the low-carbohydrate diet promoted greater improvements in blood lipids than the low-fat diet.

This is important for two reasons. First, this wasn’t a weight loss study; the researchers were simply following the subjects to see what would happen as they followed either diet. The fact that the low-carbohydrate group lost more weight suggests that it is relatively easier to cut calories following this type of diet.

This is consistent with other research showing that eating more carbohydrates, especially refined carbohydrates and sugar, can actually make people feel hungrier and eat more. Indeed, other studies have shown low-carbohydrate diets to be more effective for weight loss than low-fat diets (although a more recent study suggests there isn’t such a difference).

Second, the greater decrease in triglycerides and “bad” LDL cholesterol and increase in “good” HDL cholesterol in the low-carbohydrate group were different from what might be expected. Conventional wisdom holds that a low-fat diet should have a greater effect on blood lipids. Since weight loss can have a big effect on blood lipids, the improvement in the low-carbohydrate group may be due to losing more weight, not a direct effect of the diet.

It is important to note that the low-fat diet also led to weight loss in this and numerous other studies. The critical component of any weight loss diet is that it is relatively low in calories, regardless of what nutrients supply those calories. Really, almost any diet will lead to weight loss as long as it contains less energy than what is expended, but a low-carbohydrate diet may be more effective for weight loss than the traditional low-fat diet.

The bottom line is that the best diet is one that emphasizes eating wholesome foods, not on cutting carbohydrates or fat. That said, limiting carbohydrates in the form of refined grains and added sugar is an excellent way to reduce calorie intake and improve the overall nutritional value of what you eat. And shifting toward more monounsaturated fats (think olive oil and nuts) rather than worrying about the total amount of fat you eat is also a good idea.