Bacon and black coffee for breakfast or oatmeal and bananas?
If you plan to lose weight in 2019, you are sure to find a tough debate online and among friends and family about how best to do it. It seems that everyone has an opinion, and new fads show up every year.
Two major studies last year gave more fuel to a particularly polarizing topic – the role of carbs playing to make us fat. The studies gave scientists some traces, but as other nutrition studies, they cannot say which diet – if any – is best for everyone.
It won't satisfy people who want black-and-white answers, but nutrition research is extremely difficult, and even the most respected studies come with great reservations. People are so diverse that it is anything but impossible to carry out studies that show what really works over long periods of time.
Before starting a weight loss plan for the New Year, here's a look at some of the things that were learned last year.
FEAR CARBS, FEWER POUNDS?
It's no longer called the Atkins diet, but the low-carb school of dieting has enjoyed a comeback. The idea is that the refined carbohydrates in foods like white bread quickly turn into sugar in our bodies, leading to energy swings and hunger.
By cutting carbs, the requirement that weight loss will be easier because your body will instead burn fat to fuel while you feel less hungry. A recent study seems to offer more support for low-carb proponents. But like many studies, it tried to understand only one sliver of how the body works.
The study, led by a writer of books promoting low-carb diets, examined whether different carb levels could affect how the body uses energy. Among 164 participants, it found them on low-carb diets burned more calories in a dormant state than those on high-carb diets.
The study did not say that people lost more weight on a low-carb diet – and did not try to measure it. Meals and snacks were tightly controlled and continually adjusted so that everyone's weights remained stable.
David Ludwig, a leading author of the paper and researcher at the Boston Children's Hospital, said it suggests limiting carbs could make it easier for people to keep weight when they lost it. He said the approach might work best for those with diabetes or before diabetes.
Ludwig noted that the study was not intended to test long-term health effects or real scenarios where people make their own food. The results also need to be replicated to be validated, he said.
Caroline Apovian of Boston University's School of Medicine said the results are interesting feed for the scientific community, but that they should not be taken as a guide to the average person seeking to lose weight.
DO I AVOID FED TO BE SKINNY?
For years, people were advised to slow down fats found in foods, including meat, nuts, eggs, butter and oil. Cutting fat was seen as a way to control weight, as one gram of fat has twice as many calories than the same amount of carbohydrates or protein.
Many say the advice had the opposite effect by accidentally giving us a license to gobble up non-fat cookies, cakes and other foods that were full of the refined carbs and sugars now due to our wider waist.
Nutritionists gradually moved away from carpet recommendations to limit fat to weight loss. Fats are needed to absorb important nutrients and can help us feel full. That doesn't mean you have to subscribe to steak that drinks in butter to be healthy.
Bruce Y. Lee, professor of international health at Johns Hopkins, said that the experience of anti-fat food should be applied to the anti-carb dish: not oversimplify advice.
"There is constant looking for an easy way out," Lee said.
So what's better?
Another major study in the past year found low carb diets and fatty diets were about as effective in weight loss. The results varied individually, but after one year, people in both groups averaged 12 to 13 pounds.
The author noted that the results do not conflict with Ludvig's low carb study. Instead, they suggest that there may be some flexibility in the ways we can lose. Participants in both groups were invited to focus on minimally processed foods such as feed and meat prepared at home. All were advised to limit added sugar and refined flour.
"If you got that foundation right, for many, it would be a huge change," said Christopher Gardner from Stanford University and one of the study's authors.
Limiting processed foods can improve most diets by cutting overall calories while still waiting for people's preferences. It is important because a diet must be effective, a person must be able to stick to it. A breakfast with fruit and oatmeal can be filling for one person, but leave another hungry shortly after.
Gardner notes that the study also had its limitations. The dietary habits of the participants were not controlled. Instead, people were instructed on how to eat a low-carb or low-fat in regular meetings with dieticians, which may have provided a support network that most dieticians do not have.
So, what works?
In the short term, you can probably lose weight simply by eating raw food, or go vegan or cut gluten or follow another diet that catches your eye. But what works for you in the long term is another question.
Zhaoping Li, director of the Clinical Nutrition Division at the University of California, Los Angeles, says there is no single set of guidelines that helps everyone lose weight and keep it off. That's why dietary habits often fail – they don't take into account the many factors that drive us to eat what we do.
To help people lose weight, Li examines her patients' eating and physical activity routines to identify improvements people will be able to live with.
"What spells are what matters," Li said.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. AP is solely responsible for all content.
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