Taylor Stinson’s sheet pan Greek chicken meal prep bowls are a low-carb lunch or dinner idea with a lemon-oregano marinade, and they’re ready in 30 minutes.Taylor Stinson/The Canadian Press
Many studies have demonstrated the effectiveness of a low-carbohydrate diet for short-term weight loss. Few studies, though, have investigated how well such a diet keeps weight off long-term.
Now, a new study led by researchers from the Harvard T.H. Chan School of Public Health provides a detailed answer.
It turns out, not all low-carbohydrate diets are created equal when it comes to keeping the pounds off.
The latest research
The study, published Dec. 27 in the journal JAMA Network Open, analyzed data from 123,332 healthy adults, with an average age of 45,taking part in one of three large continuing U.S. studies – the Nurses’ Health Study, the Nurses’ Health Study II and the Health Professionals Follow-Up Study.
Participants were followed from as early as 1986 up to 2018. Diet information and body weights were collected every four years.
Based on participants’ dietary intakes, the researchers created five categories of a low-carbohydrate diet, each one emphasizing different compositions and quality of macronutrients (protein, fat, carbohydrate).
The researchers then scored how well each participant adhered to one of the five low-carb diet categories.
A “total low-carbohydrate diet” referred to simply an overall lower carbohydrate intake, regardless of macronutrient quality.
An “animal-based low-carbohydrate diet” emphasized animal proteins and fats, while a “vegetable-based low-carbohydrate diet” gave prominence to plant-based proteins and fats.
A “healthy low-carbohydrate diet” focused on plant-based proteins, healthy fats and whole grains. An “unhealthy low-carbohydrate diet,” on the other hand, emphasized animal-based proteins, unhealthy fats and refined carbohydrates.
All low-carb diets contained 38 to 40 per cent of daily calories from fat.
Healthy vs. unhealthy low-carb diets: four-year weight change
The study found that the healthy low-carbohydrate diet made up of high-quality proteins, fats and carbohydrates was tied to a slower rate of long-term weight gain than the other four low-carb diets.
Among participants who followed the unhealthy low-carbohydrate diet, those who tightened their adherence to such a plan over four years experienced even greater weight gain.
Compared with people who were least adherent to this eating pattern, those who were most adherent gained, on average, an additional 5.1 pounds over four years.
By contrast, healthy low-carbohydrate dieters who increased their adherence scores the most over four years, gained, on average, 4.9 fewer pounds compared with those whose adherence scores decreased the most.
The results were most pronounced among participants who were under age 55, overweight or obese and/or less physically active.
These findings underscore the importance of considering macronutrient quality within a low-carbohydrate diet for weight control.
Strengths and limitations
The researchers examined the link between low-carbohydrate diets and long-term weight change from a broad scope, one that considered macronutrient quality as well as quantity.
Other notable strengths were the large sample sizes and long follow-up periods of the three studies.
Limitations include the observational nature of the research, which can’t prove with certainty that following a healthy low-carbohydrate diet mitigates long-term weight gain.
Consistent with past research
This isn’t the first study to suggest that a high-quality diet makes a difference for managing weight.
An analysis of the DIETFITS trial published last year determined that people who had both high diet quality and high diet adherence were the most successful at losing excess weight, whether they followed a low-carbohydrate or low-fat diet.
And findings from the PREDIMED trial have consistently shown that a Mediterranean diet (40-per-cent carbohydrates), rich in extra virgin olive oil, fruits, vegetables, whole grains, beans and lentils, leads to greater weight loss compared with a low-fat diet (43-per-cent carbohydrates).
A high-quality diet provides more fibre that can promote satiety and reduce overall calorie intake.
Studies have also found that consuming healthy plant oils from nuts, seeds and olive oil is tied to better weight outcomes.
On the other hand, diets higher in saturated fat from animal foods have been associated with increased inflammation, insulin resistance and a higher risk of weight gain.
A diet high in refined grains and added sugars can cause rapid fluctuations in blood sugar, which could lead to hunger and overeating.
Key ingredients in a healthy low-carb diet
Highlight plant proteins such as beans, lentils, bean pastas, edamame, tofu and nuts.
Lean animal proteins include chicken, turkey, seafood, plain low-fat Greek yogurt, cottage cheese and egg whites. Limit red and processed meats.
Eat small portions of whole grains such as brown and red rice, quinoa, farro, millet and oats.
Eat plenty of non-starchy vegetables (for example, leafy greens, broccoli, cauliflower, bell peppers). Potatoes, green peas, corn, parsnips and winter squash are starchy.
Include some whole fruit, too. Berries, pomegranate seeds, cantaloupe, kiwi and citrus fruit are lower in carbohydrates.
Choose unsaturated plant oils. Extra virgin olive oil, avocado oil, peanut oil, nuts and seeds are good choices.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on X @LeslieBeckRD
The Canadian government says it will donate up to 200,000 vaccine doses to fight the mpox outbreak in Congo and other African countries.
It says the donated doses of Imvamune will come from Canada’s existing supply and will not affect the country’s preparedness for mpox cases in this country.
Minister of Health Mark Holland says the donation “will help to protect those in the most affected regions of Africa and will help prevent further spread of the virus.”
Dr. Madhukar Pai, Canada research chair in epidemiology and global health, says although the donation is welcome, it is a very small portion of the estimated 10 million vaccine doses needed to control the outbreak.
Vaccine donations from wealthier countries have only recently started arriving in Africa, almost a month after the World Health Organization declared the mpox outbreak a public health emergency of international concern.
A few days after the declaration in August, Global Affairs Canada announced a contribution of $1 million for mpox surveillance, diagnostic tools, research and community awareness in Africa.
On Thursday, the Africa Centres for Disease Control and Prevention said mpox is still on the rise and that testing rates are “insufficient” across the continent.
Jason Kindrachuk, Canada research chair in emerging viruses at the University of Manitoba, said donating vaccines, in addition to supporting surveillance and diagnostic tests, is “massively important.”
But Kindrachuk, who has worked on the ground in Congo during the epidemic, also said that the international response to the mpox outbreak is “better late than never (but) better never late.”
“It would have been fantastic for us globally to not be in this position by having provided doses a much, much longer time prior than when we are,” he said, noting that the outbreak of clade I mpox in Congo started in early 2023.
Clade II mpox, endemic in regions of West Africa, came to the world’s attention even earlier — in 2022 — as that strain of virus spread to other countries, including Canada.
Two doses are recommended for mpox vaccination, so the donation may only benefit 100,000 people, Pai said.
Pai questioned whether Canada is contributing enough, as the federal government hasn’t said what percentage of its mpox vaccine stockpile it is donating.
“Small donations are simply not going to help end this crisis. We need to show greater solidarity and support,” he said in an email.
“That is the biggest lesson from the COVID-19 pandemic — our collective safety is tied with that of other nations.”
This report by The Canadian Press was first published Sept. 13, 2024.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
HALIFAX – The Nova Scotia government says it could be months before it reveals how many people are on the wait-list for a family doctor.
The head of the province’s health authority told reporters Wednesday that the government won’t release updated data until the 160,000 people who were on the wait-list in June are contacted to verify whether they still need primary care.
Karen Oldfield said Nova Scotia Health is working on validating the primary care wait-list data before posting new numbers, and that work may take a matter of months. The most recent public wait-list figures are from June 1, when 160,234 people, or about 16 per cent of the population, were on it.
“It’s going to take time to make 160,000 calls,” Oldfield said. “We are not talking weeks, we are talking months.”
The interim CEO and president of Nova Scotia Health said people on the list are being asked where they live, whether they still need a family doctor, and to give an update on their health.
A spokesperson with the province’s Health Department says the government and its health authority are “working hard” to turn the wait-list registry into a useful tool, adding that the data will be shared once it is validated.
Nova Scotia’s NDP are calling on Premier Tim Houston to immediately release statistics on how many people are looking for a family doctor. On Tuesday, the NDP introduced a bill that would require the health minister to make the number public every month.
“It is unacceptable for the list to be more than three months out of date,” NDP Leader Claudia Chender said Tuesday.
Chender said releasing this data regularly is vital so Nova Scotians can track the government’s progress on its main 2021 campaign promise: fixing health care.
The number of people in need of a family doctor has more than doubled between the 2021 summer election campaign and June 2024. Since September 2021 about 300 doctors have been added to the provincial health system, the Health Department said.
“We’ll know if Tim Houston is keeping his 2021 election promise to fix health care when Nova Scotians are attached to primary care,” Chender said.
This report by The Canadian Press was first published Sept. 11, 2024.
ST. JOHN’S, N.L. – Newfoundland and Labrador‘s chief medical officer is monitoring the rise of whooping cough infections across the province as cases of the highly contagious disease continue to grow across Canada.
Dr. Janice Fitzgerald says that so far this year, the province has recorded 230 confirmed cases of the vaccine-preventable respiratory tract infection, also known as pertussis.
Late last month, Quebec reported more than 11,000 cases during the same time period, while Ontario counted 470 cases, well above the five-year average of 98. In Quebec, the majority of patients are between the ages of 10 and 14.
Meanwhile, New Brunswick has declared a whooping cough outbreak across the province. A total of 141 cases were reported by last month, exceeding the five-year average of 34.
The disease can lead to severe complications among vulnerable populations including infants, who are at the highest risk of suffering from complications like pneumonia and seizures. Symptoms may start with a runny nose, mild fever and cough, then progress to severe coughing accompanied by a distinctive “whooping” sound during inhalation.
“The public, especially pregnant people and those in close contact with infants, are encouraged to be aware of symptoms related to pertussis and to ensure vaccinations are up to date,” Newfoundland and Labrador’s Health Department said in a statement.
Whooping cough can be treated with antibiotics, but vaccination is the most effective way to control the spread of the disease. As a result, the province has expanded immunization efforts this school year. While booster doses are already offered in Grade 9, the vaccine is now being offered to Grade 8 students as well.
Public health officials say whooping cough is a cyclical disease that increases every two to five or six years.
Meanwhile, New Brunswick’s acting chief medical officer of health expects the current case count to get worse before tapering off.
A rise in whooping cough cases has also been reported in the United States and elsewhere. The Pan American Health Organization issued an alert in July encouraging countries to ramp up their surveillance and vaccination coverage.
This report by The Canadian Press was first published Sept. 10, 2024.
