According to new research, protein restriction is effective in combating obesity and diabetes.
According to a study comparing the effects of protein and calorie restriction diets in humans, reducing protein consumption may help control metabolic syndrome and some of its primary symptoms, such as obesity, diabetes, and high blood pressure (hypertension). The study’s findings were recently published in the journal Nutrients.
The term “metabolic syndrome” refers to a group of diseases, including hypertension, high blood sugar, excess body fat around the waist, and abnormal cholesterol levels, that increase the risk of diabetes, cardiovascular disease, and stroke.
“The study showed that cutting protein intake to 0.8 g per kg of body weight was sufficient to achieve almost the same clinical results as restricting calories, but without the need to reduce calorie intake. The results suggest that protein restriction may be one of the key factors leading to the known benefits of dietary restriction. Protein restriction dieting may therefore be a more attractive nutritional strategy and easier to follow for people with metabolic syndrome,” said Rafael Ferraz-Bannitz, first author of the article and currently a postdoctoral researcher at the Joslin Diabetes Center in Harvard Medical School in the United States.
The research involved 21 individuals with metabolic syndrome who were monitored for 27 days. Throughout the period, they were inpatients at FMRP-USP’s teaching hospital (Hospital das Clnicas in Ribeiro Preto).
The daily calorie intake of each participant was determined as a function of their baseline metabolism (energy expenditure at rest). A conventional Western diet of 50% carbohydrates, 20% protein, and 30% fat was served to one group, but it contained 25% fewer calories.
Protein consumption was lowered to 10% in the second group. Each volunteer’s calorie intake was matched to their baseline energy expenditure. 4 grams of salt were consumed daily by both groups.
The results showed that both the calorie and protein restriction groups lost weight owing to a decrease in body fat and that the symptoms of metabolic syndrome improved. Decreased body fat is known to be associated with reduced blood sugar and more normal levels of lipids and blood pressure.
“After 27 days of monitoring, both groups had similar results in terms of lower blood sugar, weight loss, controlled blood pressure, and lower levels of triglycerides and cholesterol. Both diets improved insulin sensitivity after treatment. Body fat decreased, as did waist and hip circumference, but without loss of muscle mass,” said Maria Cristina Foss de Freitas, the last author of the article and a professor at FMRP-USP.
The findings confirmed those of previous studies involving experiments on mice. “Here, however, we succeeded in conducting a fully controlled randomized clinical trial lasting 27 days, with a personalized menu designed to meet each patient’s needs,” Foss de Freitas said.
Manipulation of dietary macronutrients – protein, carbohydrate, and fat – is sufficient to obtain the beneficial effects of dietary restriction. “We demonstrated that protein restriction reduces body fat while maintaining muscle mass. That’s important since the weight loss resulting from restrictive diets is often associated with loss of muscle mass,” Ferraz-Bannitz said.
The study did not investigate the molecular mechanisms that could explain the beneficial effects of protein restriction diets, but the researchers believe low protein intake triggered a change in the metabolism or enhanced the organism’s energy management by leading it to burn fat in order to produce energy for cells. “We only have hypotheses so far. One is that molecular pathways are activated to interpret the reduction in essential amino acids as being a signal to reduce food intake while leading to the production of hormones that typically increase when we’re fasting,” Mori said. “Studies in animal models have shown the involvement of such pathways in the effects of both protein and calorie restriction, both of which lead to fat loss.”
Despite the promising results of their studies, the researchers point out that the diets involved were personalized. Mori also stressed that they focused on a specific population of patients with metabolic syndrome (obesity, diabetes, hypertension, and abnormal levels of cholesterol).
“Nevertheless, it’s tempting to extrapolate the results. We know research has shown vegan diets to be positive for cases of metabolic syndrome. It’s also been found that the excessive protein intake common in the standard Western diet can be a problem. Every case should be analyzed on its own merits. We shouldn’t forget protein deficiency can lead to severe health problems, as has been well-described in pregnant women, for example,” he added.
Reference: “Dietary Protein Restriction Improves Metabolic Dysfunction in Patients with Metabolic Syndrome in a Randomized, Controlled Trial” by Rafael Ferraz-Bannitz, Rebeca A. Beraldo, A. Augusto Peluso, Morten Dall, Parizad Babaei, Rayana Cardoso Foglietti, Larissa Marfori Martins, Patricia Moreira Gomes, Julio Sergio Marchini, Vivian Marques Miguel Suen, Luiz C. Conti de Freitas, Luiz Carlos Navegantes, Marco Antônio M. Pretti, Mariana Boroni, Jonas T. Treebak, Marcelo A. Mori, Milton Cesar Foss and Maria Cristina Foss-Freitas, 28 June 2022, Nutrients.
The study was funded by the São Paulo Research Foundation. The study also benefited from a FAPESP Thematic Project on strategies for mimicking the effects of dietary restriction, led by Marcelo Mori, a professor at the State University of Campinas (UNICAMP), also in Brazil.
A multidisciplinary team of scientists conducted the study, including researchers affiliated with the University of Copenhagen in Denmark, the University of São Paulo, and the National Cancer Institute (INCA) in Brazil, as well as the Obesity and Comorbidities Research Center (OCRC), a Research, Innovation, and Dissemination Center (RIDC) funded by FAPESP and hosted by UNICAMP.
The side-by-side “before and after” photo shown in the article isn’t from a 27-day study, is it? A little too much license was taken in this article.
WTH on this same site just published is another article about lack of protein in diets is what causes overeating and obesity.
I was thinking the same thing about the contradicting articles.
This shows how much we still don’t know about weight loss or nutrition . Studies always contradicts each new study.
I’m starting to believe that restricting one macronutrient (doesn’t matter which one) seems to work as well as (sometimes better than) caloric restriction.
I’ve seen studies claiming these types of results (or better) from low fat diets, low carb diets and low protein diets.
Perhaps it is easier to cut way back on one macro and eat to satiety than it is to count calories and eat whatever you want.
The one thing that seems consistent, is that weight loss and overall health seem to be improved much further by cutting out processed/junk foods, regardless of which diet works best for you
“I wonder how many times as a lay discoverer I must write more qualified professionals at Harvard University/Medical School before what I write is at least subjected to serious scrutiny, scientific research and/or sufficient discussion to get the word out. Meanwhile, in consideration of the article above, none of the foreign authors/researchers can be blamed for the ongoing allergy/FDA approved food poisoning ignorance and incompetence of their American counterparts, due to their non-American origins. Simply put, in the absence of my level of awareness of my kind of food and food additive sensitivities (which mainstream US medicine still fails to recognize as true [e.g., IgE mediated] allergies since the early 1930s [Dr. Arthur F. Coca]), it might be as accurate to write it was ‘allergen and toxic FDA approved food additives (e.g., added ‘cultured-free’ MSG, since 1980, and modified soy protein, minimally, since the early 1970s) deprivation’ that some of the so-called ‘protein’ patients were subjected to. Modern US medicine is still so ‘dark-ages.'”
The information here contradicts or conflicts with new findings of satiety. That being one’s lack of protein affecting appetite resulting in mistaken or misdirected hunger. Wish you could all get on the same page with the subject so we’d all be better off.
So does a deficiency of fats and carbs decrease body fat. Duh.
With so many contradictions (keto,low fat, low protein, vegetarian) maybe out problem is yrs of overconsumption and becoming sensitive to the food we consume too much? Just a thought..ppl often. Develope allergies to things they once could eat. Also the additives. Not much Natural food anymore.
The best way to lose weight is a balanced mix of good foods. I lost 36 pounds in 16 weeks on Weight Watchers in 1983 and have kept it off within 5 pounds since Ate 3 meals never hungry carbs protein veggie fruit and even a glass of wine! Ya don’t need studies to eat right and still lose weight by being healthy
This article is such progressive ‘don’t eat meat! garbage.
It implies you can stuff as much crap twinkies, cakes in your belly as you like as long as you don’t eat proteins and you’ll lose weight and balance your metabolism?
21 people over 27 days? What a home-run of a study!
How does crap like this article get noticed by media? Because Media is filled with dipheads.
Science is always changing which is why it is important for each of us to educate ourselves as much as possible. Next would be to talk to close family members and/or friends who might be more educated regarding nutrition etc. So many here are stating there is contradicting information with protein intake and weight control. I urge everyone to carefully read the other articles from this site as there is specific context that relates to this subject. Another words, this article does not contradict previous articles. Keep in mind, this site is giving us information from various sources…just like your local online news channel does.