BEST DIET : LOSE WEIGHT WITH BEST TRICK

Correction Appended: Aug. 27, 2012

The sustainable food movement is sweeping the country. Farmer’s markets, organic produce, genetically modified foods, cage-free eggs — they’ve all become part of the cultural lingo. While a lot of this conversation focuses around whether organic foods are better for people’s health, let’s not forget that these trends are also good for the planet. Read on to learn about the 33 environmentally friendly eating habits that are making a difference for our bodies and our earth.

At the store:

1. Reuse it. Bring a reusable bag on your next shopping trip, and you’ve already helped out the planet. The U.S. alone uses about 100 billion new plastic bags each year, and (brace yourself) this massive production costs 12 million barrels of oil. Worldwide, only about 1% of plastic bags are recycled — which means that the rest end up in landfills, oceans or elsewhere in the environment. Why does it matter? Plastic bags don’t biodegrade, but light exposure can degrade them enough to release toxic polymer particles — most of which end up in the ocean. Approximately 1 million birds and 100,000 turtles and other sea animals die of starvation each year after ingesting after ingesting discarded plastics and other trash debris, which block their digestive tracts. And public agencies spend millions of dollars on litter clean-up each year. (In case you’re wondering, paper bags aren’t much better. Each year, 14 million trees are cut down to make paper shopping bags via a process that requires even more energy than the making of plastic bags.)

2. Strip down. Look for products with minimal packaging, like unwrapped produce or meat straight from the deli counter or butcher. Excess packaging is often made out of unsustainable materials and contributes to waste that ends up in landfills. Perhaps the worst culprit is polystyrene (a.k.a. Styrofoam), which is a suspected carcinogen and is manufactured through an energy-intensive process that creates hazardous waste and greenhouse gases.

3. Don’t buy the bottle. Millions of tons of plastic are used to produce billions of plastic water bottles each year. Save money and lessen waste by drinking tap water from a reusable water bottle. Worried about your health? Try a water filter, or take courage from the fact that a lot of bottled water is likely no better than what’s on tap.

4. Shop different. Choose to give your money to stores that demonstrate care for the planet, both in their company practices and in the food selections they provide. Look for a selection of local and organic foods as well as store practices that limit waste (think doors on the refrigerated sections so that energy isn’t wasted, minimal and/or recyclable packaging and a store-wide recycling program).

Produce:

5. Go local. Eating locally grown foods is possibly the best way to lower your carbon footprint when it comes to what you eat. Bonus: Eating locally means that food will be fresher — and therefore taste better and perhaps retain more nutrients — than food shipped across the globe.

6. Eat more of it. Eat more produce than any other food category, and you’ve already made an impact for the planet (not to mention your body!).

7. Go organic. The definition of organic can be a little confusing, but food labels can help. Certified organic foods are grown and processed using farming methods that recycle resources and promote biodiversity, without the use of synthetic pesticides, bioengineered genes or petroleum- or sewage-sludge-based fertilizers. (Weird. Who wouldn’t want their food grown in sewage sludge?) Though their benefits to the environment have a long-term payoff, organic foods can be pricier — if you’re on a budget, find out which foods are most worth buying organic, and limit your organic purchases to the ones that make the biggest impact.

8. Eat it raw. Chomp down on a raw carrot instead of boiling or sautéing it, and save energy that would otherwise have been used to power cooking appliances.

9. Eat in season. Seasonal nomming allows you to eat locally — and we’ve already covered how important local purchasing is for the environment. Check out what’s growing nearby right now.

10. Preserve it. Want to eat more locally, but love to eat strawberries year-round? Learn how to preserve fruits and vegetables so you can eat locally grown produce all year long (it’s bound to impress Grandma, too).

11. Grow it. You don’t need to live in the wild to grow your own fruits and veggies. Join a community garden, or, if you’re cramped for space, create a vertical garden right inside your window.

12. Get some community support. Not into the idea of growing your own? Consider joining a CSA (short for community supported agriculture), which allows you to reap the benefits of locally grown produce without getting your hands dirty.

Meat:

13. Eat less of it. Industrially farmed meat has the greatest impact of any food product on the environment. In addition to the tips outlined below, consider making meat less of a staple in your diet. Can’t give up the stuff? Try going meat-free for just one day per week (or one meal per week if you’re really attached).

14. You guessed it: buy local. We’ve said it before and we’re saying it again: buying local is a great way to cut down on the environmental impact of your food. Just imagine how much energy it would take to haul a side of beef from, say, New Zealand, in comparison to transporting it from the local butcher shop.

15. Go organic. When it comes to meat, the definition of “organic” changes a little. Obviously, chickens aren’t grown in the soil, nor are they (we hope!) conventionally grown with pesticides. Rather, organic livestock must have access to the outdoors and cannot be supplemented with antibiotics or growth hormones.

16. Be anti-antibiotics. It’s common practice these days to feed growth-producing antibiotics to animals raised for meat, but this results in health risks for the animals — and, by extension, the people who eat them.

17. Go out to pasture. Pasture-raised livestock make less of a negative environmental impact. They’re also treated more humanely than their industrially raised counterparts.

Seafood:

18. Look for the label. Figuring out how to buy sustainable seafood is tough: turns out “wild caught” doesn’t necessarily mean it’s environmentally friendly, after all, while some farmed fish are. The easiest way to sort through all the confusion is to look for the label of the Marine Stewardship Council, which guarantees that a product has successfully met requirements for sustainability.

19. Know your fish. Check out these guides to figure out which fish are least endangered and most likely to be farmed sustainably, and use them to guide your buying decisions.

20. Be a patriot. Buy U.S. caught or farmed fish. It’s as close as you can get to buying “local” when you live in a land-locked state, and it also means that the product has had the chance to be reviewed by the Marine Stewardship Council, so you have a better sense of the conditions under which the fish were caught.

21. Try something new. Instead of eating the ever-popular Alaskan salmon along with everybody else at the restaurant, expand your diet and distribute your impact by trying different varieties of fish. Check out these alternatives to some of our fishy favorites — you might even find a variety that you like more than tuna. In the process, you’ll reduce the risk of endangering key species.

Dairy:

22. Be hormone-free. (Wouldn’t that have made adolescence easier…) Just as livestock raised for consumption are often pumped full of antibiotics, dairy cows are often fed artificial hormones to up their milk production. This has big health impacts for the cows, the people who consume their milk and other dairy products, and the environment (manure lagoons sure don’t sound like a good thing to us). Industrial dairy production is also linked to massive greenhouse gas emissions. Luckily, hormone-free dairy products are readily available.

23. Surprise! Go local. As always when buying local, you’ll be reducing the distance that food must travel — and the energy it takes to do so — on its way to your plate.

24. Go organic. It’s better for the environment and for your body.

25. Cut back. The production of one pound of cheese might produce upwards of 11 lbs. of carbon dioxide, the primary greenhouse gas emitted by human activities and a big driver of climate change. As with meat, you can quickly lessen your environmental impact simply by eating less dairy. Bonus: eliminating common staples from your diet one or two days a week is a chance to experiment with fun new recipes.

At a restaurant:

26. Order from the tap. Cut down on packaging; ask for tap water instead of bottled. Likewise, save the beer bottle and order on tap.

27. Eat local. Just because you’re not at the farmer’s market doesn’t mean the market’s bounty isn’t available to you. More and more restaurants are incorporating locally sourced items into their menus.

28. Don’t be afraid to ask. There’s no shame in asking your server or a manager how your food was grown or processed (though it’s probably best not to take it to this extreme).

Eating at home:

29. Reduce waste. Use cloth napkins and real plates, bowls and utensils.

30. Turn waste into a resource. If you’ve got the inclination and a little bit of free time, give composting a try and turn food scraps into a resource that keeps on giving.

31. Revamp leftovers. Instead of dumping leftovers in the trash, turn them into new meals. It’ll reduce waste and also save on the energy it would have taken to cook a different meal the next day.

32. Double your recipes. Leftovers will last twice as long, and you’ll use less energy than you would if you cooked multiple meals.

33. Cook one local meal per week. Challenge yourself to cook one meal a week (or month) that is composed completely of local ingredients. Get some friends in on the action and revel in doing something good for your health and the health of the planet.

Do you practice any of these habits on a regular basis? Have we missed any? Share your strategies for eating well for the planet in comments!

Correction: The original version of this story stated that approximately 1 million birds and 100,000 turtles and other sea animals die of starvation each year after ingesting plastic bags, which block their digestive tracts. However, any product that is littered — not just plastic bags — can pose a threat to wildlife. The story has been updated to reflect that fact.

Greatist is the fastest-growing fitness, health and happiness start-up. Check out more tips, expert opinion and fun times at Greatist.com.

Correction Appended: Aug. 27, 2012

The sustainable food movement is sweeping the country. Farmer’s markets, organic produce, genetically modified foods, cage-free eggs — they’ve all become part of the cultural lingo. While a lot of this conversation focuses around whether organic foods are better for people’s health, let’s not forget that these trends are also good for the planet. Read on to learn about the 33 environmentally friendly eating habits that are making a difference for our bodies and our earth.

At the store:

1. Reuse it. Bring a reusable bag on your next shopping trip, and you’ve already helped out the planet. The U.S. alone uses about 100 billion new plastic bags each year, and (brace yourself) this massive production costs 12 million barrels of oil. Worldwide, only about 1% of plastic bags are recycled — which means that the rest end up in landfills, oceans or elsewhere in the environment. Why does it matter? Plastic bags don’t biodegrade, but light exposure can degrade them enough to release toxic polymer particles — most of which end up in the ocean. Approximately 1 million birds and 100,000 turtles and other sea animals die of starvation each year after ingesting after ingesting discarded plastics and other trash debris, which block their digestive tracts. And public agencies spend millions of dollars on litter clean-up each year. (In case you’re wondering, paper bags aren’t much better. Each year, 14 million trees are cut down to make paper shopping bags via a process that requires even more energy than the making of plastic bags.)

2. Strip down. Look for products with minimal packaging, like unwrapped produce or meat straight from the deli counter or butcher. Excess packaging is often made out of unsustainable materials and contributes to waste that ends up in landfills. Perhaps the worst culprit is polystyrene (a.k.a. Styrofoam), which is a suspected carcinogen and is manufactured through an energy-intensive process that creates hazardous waste and greenhouse gases.

3. Don’t buy the bottle. Millions of tons of plastic are used to produce billions of plastic water bottles each year. Save money and lessen waste by drinking tap water from a reusable water bottle. Worried about your health? Try a water filter, or take courage from the fact that a lot of bottled water is likely no better than what’s on tap.

4. Shop different. Choose to give your money to stores that demonstrate care for the planet, both in their company practices and in the food selections they provide. Look for a selection of local and organic foods as well as store practices that limit waste (think doors on the refrigerated sections so that energy isn’t wasted, minimal and/or recyclable packaging and a store-wide recycling program).

Produce:

5. Go local. Eating locally grown foods is possibly the best way to lower your carbon footprint when it comes to what you eat. Bonus: Eating locally means that food will be fresher — and therefore taste better and perhaps retain more nutrients — than food shipped across the globe.

6. Eat more of it. Eat more produce than any other food category, and you’ve already made an impact for the planet (not to mention your body!).

7. Go organic. The definition of organic can be a little confusing, but food labels can help. Certified organic foods are grown and processed using farming methods that recycle resources and promote biodiversity, without the use of synthetic pesticides, bioengineered genes or petroleum- or sewage-sludge-based fertilizers. (Weird. Who wouldn’t want their food grown in sewage sludge?) Though their benefits to the environment have a long-term payoff, organic foods can be pricier — if you’re on a budget, find out which foods are most worth buying organic, and limit your organic purchases to the ones that make the biggest impact.

8. Eat it raw. Chomp down on a raw carrot instead of boiling or sautéing it, and save energy that would otherwise have been used to power cooking appliances.

9. Eat in season. Seasonal nomming allows you to eat locally — and we’ve already covered how important local purchasing is for the environment. Check out what’s growing nearby right now.

10. Preserve it. Want to eat more locally, but love to eat strawberries year-round? Learn how to preserve fruits and vegetables so you can eat locally grown produce all year long (it’s bound to impress Grandma, too).

11. Grow it. You don’t need to live in the wild to grow your own fruits and veggies. Join a community garden, or, if you’re cramped for space, create a vertical garden right inside your window.

12. Get some community support. Not into the idea of growing your own? Consider joining a CSA (short for community supported agriculture), which allows you to reap the benefits of locally grown produce without getting your hands dirty.

Meat:

13. Eat less of it. Industrially farmed meat has the greatest impact of any food product on the environment. In addition to the tips outlined below, consider making meat less of a staple in your diet. Can’t give up the stuff? Try going meat-free for just one day per week (or one meal per week if you’re really attached).

14. You guessed it: buy local. We’ve said it before and we’re saying it again: buying local is a great way to cut down on the environmental impact of your food. Just imagine how much energy it would take to haul a side of beef from, say, New Zealand, in comparison to transporting it from the local butcher shop.

15. Go organic. When it comes to meat, the definition of “organic” changes a little. Obviously, chickens aren’t grown in the soil, nor are they (we hope!) conventionally grown with pesticides. Rather, organic livestock must have access to the outdoors and cannot be supplemented with antibiotics or growth hormones.

16. Be anti-antibiotics. It’s common practice these days to feed growth-producing antibiotics to animals raised for meat, but this results in health risks for the animals — and, by extension, the people who eat them.

17. Go out to pasture. Pasture-raised livestock make less of a negative environmental impact. They’re also treated more humanely than their industrially raised counterparts.

Seafood:

18. Look for the label. Figuring out how to buy sustainable seafood is tough: turns out “wild caught” doesn’t necessarily mean it’s environmentally friendly, after all, while some farmed fish are. The easiest way to sort through all the confusion is to look for the label of the Marine Stewardship Council, which guarantees that a product has successfully met requirements for sustainability.

19. Know your fish. Check out these guides to figure out which fish are least endangered and most likely to be farmed sustainably, and use them to guide your buying decisions.

20. Be a patriot. Buy U.S. caught or farmed fish. It’s as close as you can get to buying “local” when you live in a land-locked state, and it also means that the product has had the chance to be reviewed by the Marine Stewardship Council, so you have a better sense of the conditions under which the fish were caught.

21. Try something new. Instead of eating the ever-popular Alaskan salmon along with everybody else at the restaurant, expand your diet and distribute your impact by trying different varieties of fish. Check out these alternatives to some of our fishy favorites — you might even find a variety that you like more than tuna. In the process, you’ll reduce the risk of endangering key species.

Dairy:

22. Be hormone-free. (Wouldn’t that have made adolescence easier…) Just as livestock raised for consumption are often pumped full of antibiotics, dairy cows are often fed artificial hormones to up their milk production. This has big health impacts for the cows, the people who consume their milk and other dairy products, and the environment (manure lagoons sure don’t sound like a good thing to us). Industrial dairy production is also linked to massive greenhouse gas emissions. Luckily, hormone-free dairy products are readily available.

23. Surprise! Go local. As always when buying local, you’ll be reducing the distance that food must travel — and the energy it takes to do so — on its way to your plate.

24. Go organic. It’s better for the environment and for your body.

25. Cut back. The production of one pound of cheese might produce upwards of 11 lbs. of carbon dioxide, the primary greenhouse gas emitted by human activities and a big driver of climate change. As with meat, you can quickly lessen your environmental impact simply by eating less dairy. Bonus: eliminating common staples from your diet one or two days a week is a chance to experiment with fun new recipes.

At a restaurant:

26. Order from the tap. Cut down on packaging; ask for tap water instead of bottled. Likewise, save the beer bottle and order on tap.

27. Eat local. Just because you’re not at the farmer’s market doesn’t mean the market’s bounty isn’t available to you. More and more restaurants are incorporating locally sourced items into their menus.

28. Don’t be afraid to ask. There’s no shame in asking your server or a manager how your food was grown or processed (though it’s probably best not to take it to this extreme).

Eating at home:

29. Reduce waste. Use cloth napkins and real plates, bowls and utensils.

30. Turn waste into a resource. If you’ve got the inclination and a little bit of free time, give composting a try and turn food scraps into a resource that keeps on giving.

31. Revamp leftovers. Instead of dumping leftovers in the trash, turn them into new meals. It’ll reduce waste and also save on the energy it would have taken to cook a different meal the next day.

32. Double your recipes. Leftovers will last twice as long, and you’ll use less energy than you would if you cooked multiple meals.

33. Cook one local meal per week. Challenge yourself to cook one meal a week (or month) that is composed completely of local ingredients. Get some friends in on the action and revel in doing something good for your health and the health of the planet.

Do you practice any of these habits on a regular basis? Have we missed any? Share your strategies for eating well for the planet in comments!

Correction: The original version of this story stated that approximately 1 million birds and 100,000 turtles and other sea animals die of starvation each year after ingesting plastic bags, which block their digestive tracts. However, any product that is littered — not just plastic bags — can pose a threat to wildlife. The story has been updated to reflect that fact.

Greatist is the fastest-growing fitness, health and happiness start-up. Check out more tips, expert opinion and fun times at Greatist.com.

 “It’s easy to quit smoking,” Mark Twain supposedly said. “I’ve done it hundreds of times.”

Something similar could be said of losing weight: It’s relatively easy to drop a few pounds, but keeping them off is much trickier. That explains why so many people fall into the classic pattern of yo-yo dieting, in which they lose weight, gain it back, lose it again, and so on.

A new study from researchers at Stanford University may point the way toward breaking out of this cycle. Weight loss might be more lasting, the study suggests, if dieters get the hang of certain healthy habits—such as eating mindfully and taking brief walks—before actively trying to lose weight.

The study, which appears in the Journal of Consulting and Clinical Psychology, included 267 mostly obese women who were randomly split into two groups. Half of the women began a weight-loss regimen immediately. The other half eventually followed the same regimen, but first went through an eight-week program in which they fine-tuned their lifestyle and learned to stabilize their weight.

Health.com: Little Ways to Drop the Pounds and Keep Them Off

Both groups of women ultimately slimmed down by the same amount—roughly 17 pounds, on average (or 9% of their initial body weight). But over the course of the following year, the women who participated in the eight-week program regained an average of just 3 pounds, compared to 7 pounds in the other group.

“They cut that regain in half,” says lead author Michaela Kiernan, a senior research scientist at the Stanford Prevention Research Center, in Palo Alto, Calif.

The dieting portion of the study lasted 20 weeks and featured all of the hallmarks of conventional weight-loss programs. Women met weekly with a trained instructor, kept food journals, exercised more, and followed a healthy diet focused on fruits and vegetables.

Health.com: Best Superfoods for Weight Loss

The eight-week lead-in program was unusual by comparison. Not only were the women instructed not to lose weight, but they were also told to gain it back if they did. This was designed to teach the women how to recognize and control the normal 3- to 5-pound fluctuations that occur even among people of healthy size, Kiernan says.

In addition, the women learned to control portion sizes, savor their meals, and identify healthy substitutes for their favorite high-calorie foods. To accustom the women to the ups and downs that go with dieting, the researchers even encouraged them to periodically indulge in a less-than-healthy food (like chocolate), and gave them a five-day pass—meant to simulate a vacation—during which they could eat high-calorie, high-fat foods.

“We purposely designed the study so they would do this before they lost weight,” Kiernan says. “They could see and experience what it was like, and thus obtain a sense of mastery without the pressure of having to maintain a weight loss at the same time.”

Health.com: Diet Crutches: What Works, What Doesn’t

Focusing on weight-maintenance skills before worrying about weight loss seems to have created a “teachable moment” for the study participants, says Linda Stockman, a weight-loss coach at Scott & White Healthcare, in Temple, Texas.

Often, dieters who successfully lose weight “get really excited by the weight loss, go off to enjoy it, and gain it back,” says Stockman, who was not involved in the study. “That eight weeks is a kind of cognitive behavioral approach, where they try things and experience things. And that’s the only way to get people to change their belief systems.”

The training program also may have fostered a sense of accountability and resolve heading into the weight-loss phase, says Lindsey Battistelli, manager of the weight management center at Henry Ford Health System, in Wyandotte, Mich.

“It takes effort to maintain a weight loss,” Battistelli says. “You can’t go back to doing what you were doing before. You can let yourself indulge here and there, as long as you’re willing to have it as part of a compromise.”

Health.com: Willpower Secrets From the Pros

Although the new findings are promising, Kiernan and her coauthors say their program will need to be tested in different populations. Most of the participants were white, college-educated women, making it difficult to extrapolate the findings to other women or to men.

Longer studies also are needed. Even the study participants who gained back relatively little weight tended to do so towards the end of the one-year study period, which may indicate the first signs of a relapse that wasn’t fully registered in the results, Kiernan notes.

 “It’s easy to quit smoking,” Mark Twain supposedly said. “I’ve done it hundreds of times.”

Something similar could be said of losing weight: It’s relatively easy to drop a few pounds, but keeping them off is much trickier. That explains why so many people fall into the classic pattern of yo-yo dieting, in which they lose weight, gain it back, lose it again, and so on.

A new study from researchers at Stanford University may point the way toward breaking out of this cycle. Weight loss might be more lasting, the study suggests, if dieters get the hang of certain healthy habits—such as eating mindfully and taking brief walks—before actively trying to lose weight.

The study, which appears in the Journal of Consulting and Clinical Psychology, included 267 mostly obese women who were randomly split into two groups. Half of the women began a weight-loss regimen immediately. The other half eventually followed the same regimen, but first went through an eight-week program in which they fine-tuned their lifestyle and learned to stabilize their weight.

Health.com: Little Ways to Drop the Pounds and Keep Them Off

Both groups of women ultimately slimmed down by the same amount—roughly 17 pounds, on average (or 9% of their initial body weight). But over the course of the following year, the women who participated in the eight-week program regained an average of just 3 pounds, compared to 7 pounds in the other group.

“They cut that regain in half,” says lead author Michaela Kiernan, a senior research scientist at the Stanford Prevention Research Center, in Palo Alto, Calif.

The dieting portion of the study lasted 20 weeks and featured all of the hallmarks of conventional weight-loss programs. Women met weekly with a trained instructor, kept food journals, exercised more, and followed a healthy diet focused on fruits and vegetables.

Health.com: Best Superfoods for Weight Loss

The eight-week lead-in program was unusual by comparison. Not only were the women instructed not to lose weight, but they were also told to gain it back if they did. This was designed to teach the women how to recognize and control the normal 3- to 5-pound fluctuations that occur even among people of healthy size, Kiernan says.

In addition, the women learned to control portion sizes, savor their meals, and identify healthy substitutes for their favorite high-calorie foods. To accustom the women to the ups and downs that go with dieting, the researchers even encouraged them to periodically indulge in a less-than-healthy food (like chocolate), and gave them a five-day pass—meant to simulate a vacation—during which they could eat high-calorie, high-fat foods.

“We purposely designed the study so they would do this before they lost weight,” Kiernan says. “They could see and experience what it was like, and thus obtain a sense of mastery without the pressure of having to maintain a weight loss at the same time.”

Health.com: Diet Crutches: What Works, What Doesn’t

Focusing on weight-maintenance skills before worrying about weight loss seems to have created a “teachable moment” for the study participants, says Linda Stockman, a weight-loss coach at Scott & White Healthcare, in Temple, Texas.

Often, dieters who successfully lose weight “get really excited by the weight loss, go off to enjoy it, and gain it back,” says Stockman, who was not involved in the study. “That eight weeks is a kind of cognitive behavioral approach, where they try things and experience things. And that’s the only way to get people to change their belief systems.”

The training program also may have fostered a sense of accountability and resolve heading into the weight-loss phase, says Lindsey Battistelli, manager of the weight management center at Henry Ford Health System, in Wyandotte, Mich.

“It takes effort to maintain a weight loss,” Battistelli says. “You can’t go back to doing what you were doing before. You can let yourself indulge here and there, as long as you’re willing to have it as part of a compromise.”

Health.com: Willpower Secrets From the Pros

Although the new findings are promising, Kiernan and her coauthors say their program will need to be tested in different populations. Most of the participants were white, college-educated women, making it difficult to extrapolate the findings to other women or to men.

Longer studies also are needed. Even the study participants who gained back relatively little weight tended to do so towards the end of the one-year study period, which may indicate the first signs of a relapse that wasn’t fully registered in the results, Kiernan notes.

A study shows that not all good fats are the same when it comes to protecting your health.

For decades, the message about fats has been relatively simple — reduce the amount of oils and fats you eat from animal and dairy products (less red meat and cheese) and substitute them with healthier fats from plants or fish (olive oil, omega-3 fatty acids). The difference came down to the specific type of fats that make up these foods — animal and dairy fats tend to be saturated, which means all of the free bonds available in a chain of carbon atoms are bound to hydrogen atoms, while plant fats are unsaturated, meaning some of carbon atoms have double bonds with each other. Saturated fats are more likely to build up within artery walls and form plaques that can trigger heart attacks.

But in the latest study on fats published in the BMJ, researchers found convincing evidence that not all plant fats are created equal and that linoleic acid, or omega-6 fatty acids, may be associated with a higher risk of early death from any cause, as well as increased risk of heart disease and death from heart-related conditions.

The study is actually a reanalysis of data that had not been included in the original publication of results from the Sydney Diet Heart Study, a trial that was conducted from 1966 to 1973. For more than three years, researchers at the time followed 458 men aged 30 to 59 years old who had a history of heart disease; about half were told to replace the saturated fats they consumed from animal and dairy sources with omega-6 linoleic acid, which is commonly found in safflower oil or margarines made from it. The other half were not told to change their diet in any way. When that study was published in 1978, researchers noted an increased risk of early death from any cause among the omega-6 group, but did not break down the data by what caused the deaths.

(MORE: Study: ‘Good’ Fats Even Better for the Heart Than We Thought)

So Dr. Christopher Ramsden, a clinical investigator at the National Institutes of Health, who was interested in understanding the effects of linoleic acid on heart health, contacted one of the original authors and reviewed data that had not been included in the study. This information involved deaths from heart-related causes, and the new analysis showed that the omega-6 group had a 17% higher risk of dying during the study period from heart disease, compared with 11% among the control group.

The American Heart Association (AHA) currently recommends that people replace 25% to 35% of their daily saturated-fat intake with foods containing unsaturated fats, such as canola and olive oils. The AHA further breaks down the unsaturated-fat advice by suggesting that people devote about 5% to 10% of their daily calories to foods containing linoleic acid. The recommendation is based on a review of the available data.

(MORE: Study: Eating Omega-3s May Help Reduce Alzheimer’s Risk)

The latest results, however, raise questions about that advice. Ramsden says the findings provide some refined understanding of unsaturated fats, which come in different chemical forms that may have varying benefits or risks. “I wouldn’t necessarily say that the [current advice] is necessarily completely wrong,” he says. “What happened is that in the 1960s all polyunsaturated fats were considered the same. They were grouped together under one mechanism of being able to lower blood-cholesterol levels. Then, over the ensuing decades, it became clear as science progressed that there were multiple types of polyunsaturated fats, and these compounds potentially have distinct biochemical and health effects.”

There has been some evidence to suggest that omega-6 fatty acids, for example, may trigger inflammation, a condition that is linked to an increased risk of heart problems, while omega-3 fatty acids, found in deepwater fish like salmon, tend to inhibit inflammatory reactions. Ramsden says the results highlight the need to study dietary ingredients in more detail, rather than lumping them together and assuming they have the same effect on the body.

(MORE: Can Olive Oil Help Prevent Stroke?)

Recognizing that need, the AHA says it is considering re-evaluating all its dietary recommendations, and will make the issue of polyunsaturated fats part of this assessment. Reviewing the dietary advice as a whole is important, says Alice Lichtenstein, a spokesperson for the association, since changes in one area could have unexpected, and potentially harmful, effects on other eating habits. When health organizations advised people to lower their intake of saturated fats, for example, many replaced the fats with carbohydrates, which can increase risk of diabetes and lead to higher levels of another type of fat in the blood, triglycerides. “One of the things we learned is that we need to look at the whole picture,” says Lichtenstein. “Just looking at one individual component puts undue emphasis on that component, and may lead to unanticipated consequences. We need to look at dietary patterns rather than individual nutrients or individual food components.”

Whether the association will change its advice about consuming linoleic acid isn’t clear yet, but Ramsden says the results of the latest study “could have important implications” for the way people eat if they want to stay heart-healthy.