low calorie Mediterranean diet plus exercise dec osteopenia

 There are concerns that weight loss is associated with a decreased bone mineral density (BMD) and increased osteoporosis, with the attendant clinical problems. In this light a new study found that an energy-reduced Mediterranean diet accompanied by increased physical activity mitigated the BMD decline (see bmd inc with mediter diet plus exercise  JAMA2025, or doi:10.1001/jamanetworkopen.2025.3710)

 

Details:

--924 adults aged 55-75yo with metabolic syndrome (as defined by the American Heart Assn, NHLBI, and International Diabetes Federation: hypertension, triglycerides, HDL, fasting blood glucose, and central obesity) who were overweight (BMI 27-29.9, as defined by this study) or obese (BMI 30-39.9) were randomized to an energy-reduced Mediterranean diet and increased physical activity versus an ad libitum Mediterranean diet with no physical activity promotion, as a prespecified secondary analysis of the 3-year PREDIMED-Plus clinical trial in 23 centers in Spain from 2013-2016. All were followed with dual-energy x-ray absorptiometry (DXA) scans for bone mineral density (BMD)

    -- intervention group: instructions for an energy-reduced Mediterranean diet associated with a 30% energy reduction, as well as counseling to gradually increase physical activity to 150 minutes of moderate-to-vigorous physical activity per week (specifically, to walk for a minimum of 45 minutes per day six days a week, and to engage in strength, flexibility, and balance exercises three days a week, along with 30 to 40 minute sessions of resistance training two days per week)

      -- this group also received behavioral and motivational strategies, including self-monitoring, goal-setting, and problem-solving to implement the above

 

-- Covariates assessed in the statistical analysis included age, sex, education level, marital status, smoking status, and medical history, all through questionnaires

-- mean age 65, 49% women, education level of primary school or less 50%/secondary school 30%/college 18%

-- marital status single 14%/married 75%/widowed 10%

-- diabetes 25%, hypertension 82%, hypercholesterolemia 70%, BMI 32, adherence to a Mediterranean diet at baseline 3%, energy intake in kilocalories per day 2400

-- medications: insulin or other antidiabetic medications 20%, antihypertensives 78%, lipid medications 50%, calcium and/or vitamin D 2%, osteoporotic drugs 5%

-- lifestyle: baseline physical exercise 350 METS/min/d, sedentary time two hours per day, current smokers 25% (much more in women in the control group)/former smokers 40% (much more in men than women)/ never smokers 40% (much more in women)

 

-- Main outcomes: BMD (total femur, lumbar spine, and femoral trochanter) and total bone mineral content (BMC), comparing DXA at baseline and at one and three years of follow-up, to determine the T-scores

 

Results:

-- there were insufficient numbers of patients who had osteoporosis, so statistical analyses included a combination of those with osteopenia and osteoporosis together, referred to as “low BMD status”

 

-- Total body weight:

   --Intervention group:

       -- at one year: decreased 3.5% in men and 3.0% in women

       -- at three years: decreased 3.4% in men and 2.5% in women

    -control group:

       -- at one year: decreased 0.3% in men and 0.6% in women

       -- at three years: decreased 0.5% in men and 0.9% in women

 

-- BMD changes, adjusting for the multiple covariates noted above in women, with the between-group differences:

    -- total femur BMD:

        -- one year: -0.6 (-1.9 to 0.7) g/cm2

        -- three year: 1.0 (-0.3 to 2.3) g/cm2

            -- overall p=0.05

    -- lumbar spine (L1-L4):

        -- one year: 0.2 (-1.7 to 2.2) g/cm2

        -- three year: 2.2 (-0.3 to 4.2) g/cm2

            -- overall p=0.05

    -- femoral trochanter:

        -- one year: -0.5 (-1.8 to 0.9) g/cm2

        -- three year: 1.4 (0.1 to 2.8) g/cm2

            -- overall p=0.01

 

--the above results held true in the sensitivity analyses which included only those patients who completed the studies and also those excluded participants taking calcium and/or vitamin D medication or supplementation

 

Commentary:

-- as we know, low BMD and total bone mineral content (BMC) can lead to osteoporotic fractures, increasing morbidity, diminishing quality of life, and increasing mortality rates. This issue has more importance with our aging population

    -- DXA-derived BMC, expressed in grams, is the amount of mineral in a particular skeletal site such as the femoral neck or lumbar spine, and BMD is the BMC divided by the area of the scanned region

-- several studies have shown that weight loss (especially having rapid weight loss) increases BMD loss, though this seems to be compensated in those with a moderate rate of weight loss and those maintaining vitamin D and calcium intake: https://pmc.ncbi.nlm.nih.gov/articles/PMC4217506/)

    -- low bone mass and osteoporosis was found whether the weight loss was by diet, medications (including GLP-1 receptor agonists; though this was negated with exercise: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2820308 ), or bariatric surgery (https://pmc.ncbi.nlm.nih.gov/articles/PMC9744087/)

 -- studies of intentional weight loss have found bone loss and increased fracture risk; however most studies do not find that exercise prevents that in older obese adults, including those performing resistance training or aerobic training, though resistance exercise seems to be the most effective in attenuating bone loss some: https://www.sciencedirect.com/science/article/pii/S2095254621000491?via%3Dihub

       -- it should be noted that the different studies specified different types and amounts of exercise. For example, in this last systematic review, aerobic exercise was just by walking, which in some studies had less benefit

       -- these differences in study design likely produce these quite variable and conflicting results

 

-- overall conclusions from the study:

    -- over three years, the energy-reduced Mediterranean diet plus exercise had beneficial effects on BMD in the lumbar spine among older women with metabolic syndrome and overweight or obesity

    -- the intention-to-treat analysis showed greater additional benefits in women in the femoral level as well

    -- and this was found in excluding those people taking vitamin D supplements

        -- though a study in Spain does not mean that supplemental vitamin D does not matter, given the increased potential sun exposure vs what many of us have in the northern US or Europe

    -- this is apparently the first study finding that BMD decline was mitigated in older women with a specific diet (an energy-reduced Mediterranean diet), increased physical active (prescribed, according to current guidelines, and in a very structured way), and receiving behavioral modification/motivational strategies to help adhere to all of this

        -- which means that translation of this protocol to the general population, with the expectation of finding their quite important results, is somewhat fraught without the structure and involvement of researchers

        -- and, by the way, there actually are lower rates of osteoporosis in people living in the Mediterranean regions vs their European counterparts...

 

-- another issue is that BMD is a surrogate marker for fracture risk:

    -- it is a measure of the amount of calcium across the bone studied

    -- it provides no useful information about the microstructure of the bone that provides much of the structural support

    -- it can be elevated in those with compression fractures of the spine

    -- people can have age-related increased calcium, perhaps from calcified aortas, or bony osteophytes, exaggerating the results

    -- and, people with prior fractures are highly susceptible to more fractures, even if they have normal BMD evaluations

        -- for more on this, see https://gmodestmedblogs.blogspot.com/2025/04/uspstf-new-osteoporosis-screening.html and https://gmodestmedblogs.blogspot.com/2024/06/using-surrogate-markers-for-disease-are.html

 

Limitations:

-- there were not enough people in the study who had osteoporosis to really understand the changes in that group of people

-- this study was a subsample of individuals in a larger RCT, which limits its statistical rigor

-- the study involved a specific group of people in Spain, who agreed to be in this study, and the results may not be generalizable to other groups

-- they did not do formal DXA scans of the femoral neck, just the total femur, which is an approximate surrogate

-- we have no information about baseline 25(OH) vitamin D levels (only that 2% were on supplements), and these were likely to be higher in the sun-drenched Spain, and not information about the levels of adherence to both diet and exercise

 

so,

-- yet another study finding benefit from Mediterranean diets, in this case with a low energy one having a target of 30% fewer calories (for prior blogs, see https://gmodestmedblogs.blogspot.com/search?q=mediterranean+diet )

-- and, the results from the use of this diet is probably applicable to other means of significant weight reduction (GLP-1's, surgery, other meds): an aggressive exercise program likely would help bone health a lot

-- athough i should add that red wine in moderation is typically part of the Mediterranean diet. And, the best recent studies have pretty clearly confirmed that any amount of alcohol from any beverage is potentially harmful: https://gmodestmedblogs.blogspot.com/2025/01/alcohol-and-cancers.html

 

geoff

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