various sources raising various concerns, for both prolonged high and low protein
WebMD
The Risks of High-Protein, Low-Carb Diets
Some experts have raised concern about high-protein, low-carb diets.
- High cholesterol. Some protein sources -- like fatty cuts of meat, whole dairy products, and other high-fat foods can raise cholesterol, increasing your chance of heart disease. However, studies showed that people on the Atkins diet for up to 2 years actually had decreased “bad” cholesterol levels.
- Kidney problems. If you have any kidney problems, eating too much protein puts added strain on your kidneys. This could worsen kidney function.
- Osteoporosis and kidney stones. When you're on a high-protein diet, you may urinate more calcium than normal. There are conflicting reports, but some experts think this could make osteoporosis and kidney stones more likely.
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MayoClinic
For most healthy people, a high-protein diet generally isn't harmful, particularly when followed for a short time. Such diets may help with weight loss by making you feel fuller [protein promotes satiety, and burns 1 calorie for every 4 processed]
However, the risks of using a high-protein diet with carbohydrate restriction for the long term are still being studied. Several health problems may result if a high-protein diet is followed for an extended time:
- Some high-protein diets restrict carbohydrate intake so much that they can result in nutritional deficiencies or insufficient fiber, which can cause problems such as bad breath, headache and constipation.
- Some high-protein diets include foods such as red meat and full-fat dairy products, which may increase your risk of heart disease.
- A high-protein diet may worsen kidney function in people with kidney disease because your body may have trouble eliminating all the waste products of protein metabolism.
If you want to follow a high-protein diet, choose your protein wisely. Good choices include soy protein, beans, nuts, fish, skinless poultry, lean beef, pork and low-fat dairy products. Avoid processed meats.
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Diet high in protein, processed meat raises risk of diabetes
Lisbon, Portugal - Results of a large population-based study show that a high protein intake is associated with an increased incidence of type 2 diabetes. In presenting their results here at the European Association for the Study of Diabetes (EASD) 2011 Meeting, Swedish researchers suggest that replacing protein with carbohydrates, especially breads and cereals rich in fiber, may be preferable for avoiding incident diabetes.
Diets low in carbohydrates but high in protein and fat have shown positive effects on weight reduction and glycemic control, but other studies have shown that a high protein intake, especially animal protein such as processed meats, is associated with an increased risk of type 2 diabetes.
Lead author Ulrika Ericson (Lund University, Malmö, Sweden) told meeting attendees that the study included 27 140 individuals (10 550 men) 45 to 73 years old who participated in the Malm ö Diet and Cancer Cohort and did not have diabetes at baseline. The researchers gathered information on weight, height, lifestyle, and socioeconomic factors. Dietary data were obtained through a seven-day registration of cooked meals, a detailed 168-item questionnaire covering other meals, and a 45-minute interview.
Between 1991 and 2006, 1709 incident cases of type 2 diabetes were identified. Using a Cox proportional hazards model with adjustment for several potential confounders, researchers found that, for both genders, participants with the highest intakes of protein were at increased risk of developing diabetes, Ericson told the audience. The highest quintile of protein intake was associated with a 37% increased risk of type 2 diabetes compared with the lowest quintile (hazard ratio =1.37; p for trend <0.001).
High intake of processed meat was also associated with an elevated risk of diabetes (p=0.01), as was intake of poultry and eggs. There was no association of diabetes risk with intake of fish or red meat, but when all animal sources of dietary protein were considered together, an increased risk was seen. "So this indicates that protein per se may be of importance," Ericson concluded.
"For carbohydrate intake, we did not find any overall association with type 2 diabetes," she said. "However, we found significant interaction with sex (p=0.02). In men, high carbohydrate intake tended to be protective," reducing the risk of type 2 diabetes by about 23%. There was no significant effect of carbohydrate intake for women. Overall, fat intake was not associated with the risk of incident diabetes, but there was trend toward protection for women in the highest quintile of fat intake.
For both men and women, fiber intake was not associated with any change in risk, but the intake of fiber-rich breads and cereals showed a significant association with reduced risk of type 2 diabetes, with the highest quintile of intake having an HR of approximately 0.71 (p=0.002).
In summary, Ericson said a protective association exists with a high intake of fiber-rich breads and cereals. And although high protein intake has been shown to be effective for short-term weight loss and glycemic control, it is associated with an increased risk of type 2 diabetes. So the results of this trial suggest caution when considering high-protein diets. However, she said it is too early to make dietary recommendations based merely on the observed associations.
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GoAskAlice
Dear SMS,
Beans, seafood, poultry, meat, and eggs. These are just a few sources for protein. Our bodies need protein for numerous functions. Hemoglobin, which carries oxygen, is an essential protein that gives blood its red color when oxygenated. Antibodies, which act as defenders against disease, are composed of proteins. Hormones, some of which are made from amino acids (the building blocks of protein), regulate many systems in our bodies. These include the regulation of metabolism, digestion, and nutrient absorption, and the concentration of blood glucose. Proteins are also used by our cells to regulate the distribution of water and the movement of nutrients in and out of cells, particularly since proteins are one of the components of cell membranes. Furthermore, proteins are involved in blood clotting, acid-base balance, and visual pigmentation.
Considering we need protein to help our bodies carry out and sustain essential physiological functions, a diet very low in protein is obviously not a good idea. The good news is that it is not difficult to obtain sufficient protein from our diet and most Americans have no trouble doing so. Dietary protein can be obtained from animal and vegetable sources. If your diet is insufficient in protein, you could also be deficient in many important vitamins and minerals found in protein-rich foods. Deficiencies could occur in niacin, thiamin, riboflavin, B-12, B-6, iron, zinc, and calcium, among others, depending on what foods are missing from your diet. The effects of prolonged low protein in the diet would eventually manifest themselves as impaired immune function, and irregularities in other bodily functions and systems described above.