Summary: When designing a dietary strategy for weight loss and maintenance the individual patient’s functional and genetic constitution must be carefully considered, but there is an accumulation of evidence indicating that a high protein, low carbohydrate regimen is a good starting point.

There is a large body of evidence that can instruct us in how to fashion an eating plan to promote both short and long-term success in weight loss and healthy body composition. As a paper published in the journal Obesity demonstrates, the way many Americans eat—referred to as a ‘cafeteria diet’ (CF)—is worse than a diet high in lard. The authors note:

“Obesity has reached epidemic proportions worldwide and reports estimate that American children consume up to 25% of calories from snacks. Several animal models of obesity exist, but studies are lacking that compare high-fat diets (HFD) traditionally used in rodent models of diet-induced obesity (DIO) to diets consisting of food regularly consumed by humans, including high-salt, high-fat, low-fiber, energy dense foods such as cookies, chips, and processed meats.”

They investigated the effects on weight gain and inflammation of a cafeteria diet (CAF) compared to a lard-based 45% HFD by feeding their rodent models either HFD, CAF or a chow control for 15 weeks. Their data clearly show that even consuming almost half the diet in lard is better than the lethal mix that many now consume:

“Body weight increased dramatically and remained significantly elevated in CAF-fed rats compared to all other diets. Glucose- and insulin-tolerance tests revealed that hyperinsulinemia, hyperglycemia, and glucose intolerance were exaggerated in the CAF-fed rats compared to controls and HFD-fed rats.”

Moreover, the cafeteria diet was markedly worse in promoting inflammation:

“It is well-established that macrophages infiltrate metabolic tissues at the onset of weight gain and directly contribute to inflammation, insulin resistance, and obesity. Although both high fat diets resulted in increased adiposity and hepatosteatosis, CAF-fed rats displayed remarkable inflammation in white fat, brown fat and liver compared to HFD and controls. In sum, the CAF provided a robust model of human metabolic syndrome compared to traditional lard-based HFD, creating a phenotype of exaggerated obesity with glucose intolerance and inflammation.”

A study published in The New England Journal of Medicine examined specific dietary factors that stand out in their contribution to obesity noting that they…

“…may affect the success of the straightforward-sounding strategy “eat less and exercise more” for preventing long-term weight gain.”

They performed investigations involving 120,877 U.S. women and men who were free of chronic diseases and not obese at baseline for as long as twenty years. Relationships between changes in lifestyle factors and weight change were evaluated every four years. There were several factors that stood out:

“Within each 4-year period, participants gained an average of 3.35 lb. On the basis of increased daily servings of individual dietary components, 4-year weight change was most strongly associated with the intake of potato chips (1.69 lb), potatoes (1.28 lb), sugar-sweetened beverages (1.00 lb), unprocessed red meats (0.95 lb), and processed meats (0.93 lb) and was inversely associated with the intake of vegetables (−0.22 lb), whole grains (−0.37 lb), fruits (−0.49 lb), nuts (−0.57 lb), and yogurt (−0.82 lb)…Other lifestyle factors were also independently associated with weight change, including physical activity (−1.76 lb across quintiles); alcohol use (0.41 lb per drink per day), smoking (new quitters, 5.17 lb; former smokers, 0.14 lb), sleep (more weight gain with <6 or >8 hours of sleep), and television watching (0.31 lb per hour per day).”

Potatoes are clearly ‘sugar grenades’, but in my opinion further studies are required to examine the difference between red meat from animals treated with hormones and fed a grain diet versus those that are free of growth-stimulating medications and eat mainly grass.

With the most egregious insults to a metabolically healthy diet out of the way, we can proceed to the roles of glycemic index and glycemic load on weight loss as examined in a study published recently in the Journal of Nutrition:

“This study assessed the effect of changes in glycemic index (GI) and load (GL) on weight loss and glycated hemoglobin (HbA1c) among individuals with type 2 diabetes beginning a vegan diet or diet following the 2003 American Diabetes Association (ADA) recommendations.”

99 subjects with type 2 diabetes were randomized to follow 1 of 2 diet treatments for 22 weeks. Glycemic index and glycemic load changes were assessed and their relationships with changes in weight and HbA1C were calculated. (Glycemic index is a metric for rate which a food will cause blood sugar to rise. Glycemic load is determined by multiplying the glycemic index by the amount of carbohydrate in grams provided by a food and dividing the total by 100; this amounts to the sum of the glycemic loads for all foods consumed in the diet.) Interestingly, glycemic index predicted weight gain while glycemic load did not:

“…the vegan group reduced GI to a greater extent than the ADA group, but GL was reduced further in the ADA than the vegan group. GI predicted changes in weight, adjusting for changes in fiber, carbohydrate, fat, alcohol, energy intake, steps per day, group, and demographics, such that for every point decrease in GI, participants lost ~0.2 kg (0.44 lb)…Weight loss was a predictor of changes in HbA1C. GL was not related to weight loss or changes in HbA1C.”

Thus glycemic index takes precedence over glycemic load in choosing foods for weight loss and blood sugar regulation. Also notable was the finding regarding GI and HbA1C:

“GI was not a predictor for changes in HbA1C after controlling for weight loss.”

Every wonder why a patient’s HbA1C didn’t go down even though they were eating a low GI diet? This shows that if they don’t lose weight as a result, the the HbA1C will tend to stay the same. The authors conclude:

“A low-GI diet appears to be one of the determinants of success of a vegan or ADA diet in reducing body weight among people with type 2 diabetes. The reduction of body weight, in turn, was predictive of decreasing HbA1C.”

The interesting difference between the effects of glycemic index and glycemic load revealed here help to explain the inconsistency noted in a review published earlier in journal IUBMB (International Union of Biochemistry and Molecular Biology) Life:

“Recently, due to its possible link to appetite control and metabolism, several clinical studies have assessed the effect of low glycemic index (GI) and glycemic load (GL) diets on weight loss. To determine the application of GI/GL in the prevention and treatment of obesity, we searched several databases and identified 23 clinical trials that examined low GI/GL diets and weight loss as the primary outcome measure.”

Here the pooling of GI and GL seems to have obfuscated the issue. The authors conclude:

“Over the past decade, the body of research that links low GI/GL diets to weight loss has grown rapidly and significantly. While there is a significant amount of inconsistency in the current findings, the majority of studies found a trend that favored low GI/GL diets in weight loss.”

Moreover…

“…the benefits of low GI and GL diets extend beyond weight loss and have favorable effects on obesity-related risk factors such as heart disease and diabetes by mechanisms that are independent of weight loss.”

What about protein versus carbohydrate for weight loss? A number of investigators have examined this question, but an interesting study published recently in the Nutrition Journal corrects some important limitations in earlier work:

“Studies have suggested that moderately high protein diets may be more appropriate than conventional low-fat high carbohydrate diets for individuals at risk of developing the metabolic syndrome and type 2 diabetes. However in most such studies sources of dietary carbohydrate may not have been appropriate and protein intakes may have been excessively high. Thus, in a proof-of-concept study we compared two relatively low-fat weight loss diets – one high in protein and the other high in fiber-rich, minimally processed cereals and legumes – to determine whether a relatively high protein diet has the potential to confer greater benefits.”

They eighty-three overweight or obese women to either a moderately high protein (30% protein, 40% carbohydrate) diet (HP) or to a high fiber, relatively high carbohydrate (50% carbohydrate, > 35 g total dietary fiber, 20% protein) diet (HFib) for 8 weeks. During that time their energy intakes were reduced by 478 to 955 calories per day to achieve weight loss of between 0.5 and 1 kg per week. Which diet resulted in better weight loss?

“Participants on both diets lost weight (HP: -4.5 kg and HFib: -3.3 kg), and reduced total body fat (HP: -4.0 kg and HFib: -2.5 kg, and waist circumference (HP: -5.4 cm and HFib: -4.7 cm), as well as total and LDL cholesterol, triglycerides, fasting plasma glucose and blood pressure. However participants on HP lost more body weight (-1.3 kg) and total body fat (-1.3 kg). Diastolic blood pressure decreased more on HP (-3.7 mm Hg).”

High protein wins out over high carbohydrate, even when the carbohydrate is high fiber. The authors conclude:

“A realistic high protein weight-reducing diet was associated with greater fat loss and lower blood pressure when compared with a high carbohydrate, high fiber diet in high risk overweight and obese women.”

Importantly, the benefits of a high protein to carbohydrate ratio diet include the slowing of tumor growth and prevention of cancer initiation as described in an excellent paper (you may wish to read it in its entirety) published recently in the journal Cancer Research. It includes a significant consideration for reducing carbohydrate by increasing protein rather than fat. The authors state:

“Since cancer cells depend on glucose more than normal cells, we compared the effects of low carbohydrate (CHO) diets to a Western diet on the growth rate of tumors in mice. To avoid caloric restriction–induced effects, we designed the low CHO diets isocaloric with the Western diet by increasing protein rather than fat levels because of the reported tumor-promoting effects of high fat and the immune-stimulating effects of high protein.”

They were able to formulate diets that demonstrated that the tumor inhibiting effects were due to factors other than weight loss from calorie restriction (CR):

“To exploit the fact that cancer cells rely more heavily on glycolysis than normal cells, we designed low CHO, high protein diets to see if we could limit BG and tumor growth. In designing our diets, we wanted to avoid NCKDs [no calorie ketogenic diets] because of the difficulty in achieving long-term compliance with no CHO diets in potential future human studies and because Masko and colleagues recently reported that a 10% or 20% CHO diet slows tumor growth as effectively as NCKDs. Following early studies with 8% CHO diets, using 10% and 15% CHO, high protein diets in which 70% of the CHO was in the form of amylose, we found that, compared with a Western diet, they were indeed capable of reducing BG, insulin, and lactate levels and, importantly, in slowing the growth of implanted murine and human tumors, with little or no effects on mouse weight.”

There is good reason to apply these finding to human case management:

“Consistent with the notion that reducing BG in humans can be beneficial, there is a wealth of epidemiologic evidence showing a clear association between BG and/or insulin levels (which are determined by BG levels) and the incidence of human cancers. Thus, although our studies were conducted, out of necessity, with mice, the fact that human BG can be significantly reduced with low CHO diets and the association of many cancers with high BG levels suggest that our findings are very likely relevant to human cancers as well, particularly in cancers that have been associated with higher baseline BG and/or insulin levels, such as pancreatic, breast, colorectal, endometrial, and esophageal cancers.”

This also has application to prostate cancers:

“In addition to these cancers, a low CHO diet may also be beneficial in early-stage prostate cancer, even though it is not typically detectable by PET. This is because the metastases of these tumors kill the patients and, given the pivotal role of lactate in promoting metastasis, our low CHO diets could significantly reduce metastasis by reducing tumor-associated lactate levels.”

Regarding concerns about the impact on kidney function…

“In terms of macronutrient composition, even though high protein has been shown to promote satiety—thus reducing obesity, BG, and insulin levels—and enhance both antitumor immunity, through amino acid supplementation, and life span, we were concerned, based on the literature, that high protein levels might cause kidney damage. More recent data, however, suggest that this may only occur in individuals with existing chronic kidney disease and that in normal people, the increase in glomerular filtration rate and kidney cellularity that occur with long-term high protein consumption may be a normal response.”

Incidentally, amylose starch prevents DNA damage in the colon that may otherwise be caused by red meat:

“Interestingly, colonic cancer-inducing damage caused by red meats may be avoided with high amylose, low CHO diets. These studies suggest that macronutrient sources and combinations are very important…”

The authors conclude:

“Our study, herein, shows that a high amylose containing low CHO, high protein diet reduces BG, insulin, and glycolysis, slows tumor growth, reduces tumor incidence, and works additively with existing therapies without weight loss or kidney failure. Such a diet, therefore, has the potential of being both a novel cancer prophylactic and treatment, warranting further investigation of its applicability in the clinic, especially in combination with existing therapies.”

Regarding weight loss, what if exercise is added to the program? Will high protein still beat high carbohydrate. A study published in the journal The Physician and Sports Medicine studies this question as the authors set out to…

“…determine whether sedentary obese women with elevated levels of homeostatic model assessment (HOMA) insulin resistance (ie, > 3.5) experience greater benefits from an exercise + higher-carbohydrate (HC) or carbohydrate-restricted weight loss program than women with lower HOMA levels.”

221 women who participated in a 10-week supervised exercise and weight loss program were assigned low-fat (30%) diets that consisted of 1200 kcals per day for 1 week (phase 1) and 1600 kcals per day for 9 weeks (phase 2) with either high carbohydrate (HC) or higher protein (HP). Fasting blood samples, body composition, anthropometry, resting energy expenditure, and fitness measurements were obtained at the beginning and end. Again we see high protein win out over high carbohydrate:

“Subjects in the HP group experienced greater weight loss (−4.4 ± 3.6 kg vs −2.6 ± 2.9 kg), fat loss (−3.4 ± 2.7 kg vs −1.7 ± 2.0 kg), reductions in serum glucose (3% vs 2%), and decreases in serum leptin levels (−30.8% vs −10.8%) than those in the HC group.”

The authors conclude:

“A carbohydrate-restricted diet promoted more favorable changes in weight loss, fat loss, and markers of health in obese women who initiated an exercise program compared with a diet higher in carbohydrate. Additionally, obese women who initiated training and dieting with higher HOMA levels experienced greater reductions in blood glucose following an HP diet.”

Regarding the use of vegetable or fruit juices in programs designed for weight loss, a study published in the journal Obesity demonstrates that this is counter-productive:

“Beverage consumption has been implicated in weight gain, but questions remain about the veracity of the association, whether the relationship is causal and what property of beverages is responsible. It was hypothesized that food form is the most salient attribute. Thus, a randomized controlled trial of food form was conducted. Energy-matched beverage or solid forms of fruits and vegetables were provided to 34, lean or overweight/obese adults for two 8-week periods with a 3-week washout interspersed.”

During the solid food arm of the study the lean group had no significant weight change while the overweight/obese group had weight gain, but during the juice phase…

“In contrast, incomplete dietary compensation and weight gain occurred in both the lean (43%) and overweight/obese (61%) groups during the beverage arm…These data demonstrate energy consumed as beverages may be especially problematic for weight gain.”

And for the carbohydrates that are consumed, a curious study also published in Obesity offers evidence that eating them mainly at dinner further aids in weight loss, satiety and more:

“This study was designed to investigate the effect of a low-calorie diet with carbohydrates eaten mostly at dinner on anthropometric, hunger/satiety, biochemical, and inflammatory parameters. Hormonal secretions were also evaluated. Seventy-eight police officers (BMI >30) were randomly assigned to experimental (carbohydrates eaten mostly at dinner) or control weight loss diets for 6 months. On day 0, 7, 90, and 180 blood samples and hunger scores were collected every 4 h from 0800 to 2000 hours. Anthropometric measurements were collected throughout the study.”

Amazingly…

“Greater weight loss, abdominal circumference, and body fat mass reductions were observed in the experimental diet in comparison to controls. Hunger scores were lower and greater improvements in fasting glucose, average daily insulin concentrations, and homeostasis model assessment for insulin resistance (HOMAIR), T-cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels were observed in comparison to controls. The experimental diet modified daily leptin and adiponectin concentrations compared to those observed at baseline and to a control diet.”

Wow…all that just from shifting carbohydrates to dinner. The authors conclude:

“A simple dietary manipulation of carbohydrate distribution appears to have additional benefits when compared to a conventional weight loss diet in individuals suffering from obesity. It might also be beneficial for individuals suffering from insulin resistance and the metabolic syndrome.”

The scientific data addressing various aspects of dietary fat is treated in a separate post, but it’s suitable here to consider a study published in The Journal of Clinical Endocrinology & Metabolism offering evidence that a low carbohydrate diet is equivalent to a low fat diet for weight loss:

“Overweight and obese men and women (24–61 yr of age) were recruited into a randomized trial to compare the effects of a low-fat (LF) vs. a low-carbohydrate (LC) diet on weight loss…Subjects on the LF diet consumed an average of 17.8% of energy from fat, compared with their habitual intake of 36.4%, and had a resulting energy restriction of 2540 kJ/d [585 calories]. Subjects on the LC diet consumed an average of 15.4% carbohydrate, compared with habitual intakes of about 50% carbohydrate, and had a resulting energy restriction of 3195 kJ/d [763 calories].”

At the end of the study period the LC group lost as much weight and had better insulin regulation:

“Both groups of subjects had significant weight loss over the 10 wk of diet intervention and nearly identical improvements in body weight and fat mass. LF subjects lost an average of 6.8 kg and had a decrease in body mass index of 2.2 kg/m2, compared with a loss of 7.0 kg and decrease in body mass index of 2.1 kg/m2 in the LC subjects. The LF group better preserved lean body mass when compared with the LC group; however, only the LC group had a significant decrease in circulating insulin concentrations.”

The authors conclude:

“”These data suggest that energy restriction achieved by a very LC diet is equally effective as a LF diet strategy for weight loss and decreasing body fat in overweight and obese adults.”

Bottom line: When designing a dietary strategy for weight loss and maintenance the individual patient’s functional and genetic constitution must be carefully considered (inflammation, immune regulation, insulin sensitivity, allergy, intestinal permeability, sleep disordered breathing and hormonal function are fundamentals); but there is an accumulation of evidence suggesting that a high protein, low carbohydrate regimen is a good starting point.

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More evidence that dairy foods contain agents with antiinflammatory and antioxidant properties is presented in a study published recently in The American Journal of Clinical Nutrition showing reductions in damaging inflammatory biomarkers. The authors state:

“Oxidative and inflammatory stress are elevated in obesity and are further augmented in metabolic syndrome. We showed previously that dairy components suppress the adipocyte- and macrophage-mediated generation of reactive oxygen species and inflammatory cytokines and systemic oxidative and inflammatory biomarkers in obesity…The objective of this study was to determine the early (7 d) and sustained (4 and 12 wk) effects of adequate-dairy (AD) compared with low-dairy (LD) diets in subjects with metabolic syndrome.”

Their forty overweight or obese subjects with metabolic syndrome were randomly assigned to receive either an ‘adequate dairy diet’ (defined as 3.5 daily servings) or ‘low dairy diet’ (less than half a daily serving) form of weight-maintenance diet for 12 weeks. They measured oxidative and inflammatory biomarkers at the start and after 1, 4, and 12 weeks as primary outcomes, along with body weight and composition to start and after 4, and 12 weeks as secondary outcomes. Their data showed a dramatic difference for the ‘adequate dairy’ diet:

“AD decreased malondialdehyde and oxidized LDL at 7 d (35% and 11%, respectively), with further decreases by 12 wk. Inflammatory markers were suppressed with intake of AD, with decreases in tumor necrosis factor-α at 7 d and further reductions through 12 wk (35%); decreases in interleukin-6 (21%) and monocyte chemoattractant protein 1 (14% decrease at 4 wk, 24% decrease at 12 wk); and a corresponding 55% increase in adiponectin at 12 wk. LD exerted no effect on oxidative or inflammatory markers. Diet had no effect on body weight; however, AD significantly reduced waist circumference and trunk fat, and LD exerted no effect.”

While these findings don’t obviate the need to attend to the possibility of dairy allergies or the quality of dairy foods consumed, this is strong evidence that there agents in an ‘adequate dairy’ diet that can do more than a low dairy diet even when the same amount of weight is lost.

“Data from this study show that an increase in dairy intake from suboptimal to adequate levels (≈3.5 servings/d) significantly attenuates both oxidative and inflammatory stress in metabolic syndrome. Notably, although these effects may result, in part, from reductions in adiposity on higher dairy diets, the rapid onset (within the first 7 d of dietary change) suggest that there is an adiposity-independent effect as well. This is further supported by our previous evidence that showed direct effects of dairy components on adipocyte cytokine expression and secretion.”

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Original research published recently in the Annals of Internal Medicine offers evidence that trans-palmitoleate, a fat present in milk, is responsible for metabolic benefits observed with dairy consumption. The authors set out to…

“…To investigate whether circulating trans-palmitoleate is independently related to lower metabolic risk and incident type 2 diabetes.”

They examined 3736 adults in the Cardiovascular Health Study for plasma phospholipid fatty acids, blood lipids, inflammatory markers, and glucose–insulin and dietary habits, taking into consideration relevant demographic, clinical, and lifestyle factors. They then determined how trans-palmitoleate related to major metabolic risk factors. Their data tell an interesting story of a helpful fat:

“In multivariate analyses, whole-fat dairy consumption was most strongly associated with higher trans-palmitoleate levels. Higher trans-palmitoleate levels were associated with slightly lower adiposity and, independently, with higher high-density lipoprotein cholesterol levels, lower triglyceride levels, a lower total cholesterol–HDL cholesterol ratio, lower C-reactive protein levels, and lower insulin resistance. Trans-palmitoleate was also associated with a substantially lower incidence of diabetes…Protective associations with metabolic risk factors were confirmed in the validation cohort.”

Of course, this study does address the widespread problem of dairy allergy, nor does it discriminate between the widely varying qualities of dairy (organic from grass-fed free-range animals versus industrial dairy). But it does caution against the wholesale discrimination against fats in general and the dairy food group in particular. As always, clinical and lifestyle decisions depend on the needs of the individual which can be verified by objective outcome markers. Practitioners and health conscious individuals can consider the authors’ conclusion:

“Circulating trans-palmitoleate is associated with lower insulin resistance, presence of atherogenic dyslipidemia, and incident diabetes. Our findings may explain previously observed metabolic benefits of dairy consumption and support the need for detailed further experimental and clinical investigation.”

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An international study just published in The New England Journal of Medicine provides the most robust evidence so far that a high protein + low glycemic index diet is best for weight maintenance. The authors observe:

“Studies of weight-control diets that are high in protein or low in glycemic index have reached varied conclusions, probably owing to the fact that the studies had insufficient power.”

773 overweight adults from eight European countries who completed an initial low-calorie weight loss phase were randomized to follow one of five diets for weight maintenance: a low-protein and low-glycemic-index diet, a low-protein and high-glycemic-index diet, a high-protein and low-glycemic-index diet, a high-protein and high-glycemic-index diet, or a control diet. The diets were ‘ad libitum’, meaning they were allowed to eat freely within the constraints of their diet plan. What did the data show?

“…only the low-protein–high-glycemic-index diet was associated with subsequent significant weight regain. In an intention-to-treat analysis, the weight regain was 0.93 kg less in the groups assigned to a high-protein diet than in those assigned to a low-protein diet and 0.95 kg less in the groups assigned to a low-glycemic-index diet than in those assigned to a high-glycemic-index diet.”

Moreover, it seems that the high-protein and low-glycemic-index groups were more comfortable:

“Fewer participants in the high-protein and the low-glycemic-index groups than in the low-protein–high-glycemic-index group dropped out of the study.”

Thus the authors conclude:

“In this large European study, a modest increase in protein content and a modest reduction in the glycemic index led to an improvement in study completion and maintenance of weight loss.”

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A paper just published in the Canadian Medical Association Journal offers another reason to eat that are high in healthy monounsaturated fats like olive oil, avocados, nuts and seeds. The authors state:

“We tested whether increasing the monounsaturated fat content of a diet proven effective for lowering LDL cholesterol (dietary portfolio) also modified other risk factors for cardiovascular disease, specifically by increasing HDL cholesterol, lowering serum triglyceride and further reducing the ratio of total to HDL cholesterol.”

They randomly assigned 24 patients with excessive blood fats (hyperlipidemia) to a diet either high or low in monounsaturated fatty acids (MUFA) for a month and acquired this data:

“For patients who consumed the dietary portfolio high in monounsaturated fat, HDL cholesterol rose [12.5%], whereas for those consuming the dietary portfolio low in monounsaturated fat, HDL cholesterol did not change…Patients consuming the diet high in monounsaturated fat also had significantly higher concentrations of apolipoprotein AI, and their C-reactive protein was significantly lower.”

This makes eating good (monounsaturated) fats better than any medication; olive oil is an especially ‘medicinal’ food considering that it has other compounds also proven beneficial (type ‘olive oil’ into the search box above). The authors conclude:

“Monounsaturated fat increased the effectiveness of a cholesterol-lowering dietary portfolio, despite statin-like reductions in LDL cholesterol. The potential benefits for cardiovascular risk were achieved through increases in HDL cholesterol, further reductions in the ratio of total to HDL cholesterol and reductions in C-reactive protein.”

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Most readers here probably understand that the biological response to skipping breakfast does widespread damage to the body. It provokes a catabolic (‘tearing down’) sympathetic nervous system response as the brain forces the breakdown of muscle tissue with ‘fight or flight’ chemicals (catecholamine neurotransmitters) to satisfy its need for steady glucose (gluconeogenesis). Meanwhile, weight loss is defeated by the suppression of thyroid function as an adaptation to perceived ‘famine’. A study just published in the American Journal of Clinical Nutrition documents the long-term negative cardiovascular effects:

“The objective was to examine longitudinal associations of breakfast skipping in childhood and adulthood with cardiometabolic risk factors in adulthood.”

2184 Australian children were followed over a period of twenty years into young adulthood. Skipping breakfast was defined as not eating between 0600 and 0900. Differences in mean waist circumference and blood glucose, insulin, and lipid concentrations were calculated (after controlling for relevant confounding variables). What did the data show?

“…participants who skipped breakfast in both childhood and adulthood had a larger waist circumference and higher fasting insulin, total cholesterol, and LDL cholesterol concentrations than did those who ate breakfast…”

This certainly makes sense in consideration of the compensatory blood sugar and insulin reaction to the hypoglycemic state imposed by failing to ‘break’ the nighttime ‘fast’ in the morning.

The authors conclude by stating:

“Skipping breakfast over a long period may have detrimental effects on cardiometabolic health. Promoting the benefits of eating breakfast could be a simple and important public health message.”

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As the authors of research just published in the American Journal of Clinical Nutrition state:

“Several studies suggest that carbohydrate nutrition is related to oxidative stress and inflammatory markers.”

The proceeded to examine whether dietary glycemic index (GI), dietary fiber, and carbohydrate-containing food groups were associated with death due to non-cardiovascular, non-cancer inflammatory disease in 1490 postmenopausal women and 1245 men. What did their data show?

“Over a 13-y period, 84 women and 86 men died of inflammatory diseases. Women in the highest GI tertile had a 2.9-fold increased risk of inflammatory death…Increasing intakes of foods high in refined sugars or refined starches and decreasing intakes of bread and cereals or vegetables other than potatoes also independently predicted a greater risk. In men, only an increased consumption of fruit fiber and fruit conferred an independent decrease in risk of inflammatory death.”

In other words, for postmenopausal women the high glycemic index diet almost tripled the risk of death from inflammatory disease.

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Studies examining the epidemiological effect of a food rarely disclose its quality and source. Do you ever wonder if a study on meat, for example, might give different results if the subjects consumed only organic grass-fed meat rather than meat from hormone and antibiotic-laced feedlot animals fed on grain silage and offal? A study recently published in the European Journal of Clinical Nutrition came up with a surprise when it investigated the effect of full-fat dairy on cardiovascular disease in Australian adults.

“Dairy foods contain various nutrients that may affect health. We investigated whether intake of dairy products or related nutrients is associated with mortality due to cardiovascular disease (CVD), cancer and all causes.”

The authors studied 1529 adult Australians over 16 years, correlating habitual intakes of dairy products with mortality and cause of death. When the numbers were analyzed an unexpected finding emerged:

“…compared with those with the lowest intake of full-fat dairy, participants with the highest intake had reduced death due to CVD after adjustment for calcium intake and other confounders.”

The data compelled them to record conclusions contrary to popular dogma:

“Overall intake of dairy products was not associated with mortality. A possible beneficial association between intake of full-fat dairy and cardiovascular mortality needs further assessment and confirmation.”

Perhaps it has something to with what the cows were eating. A study published just last month in the journal Veterinary Research Communications compared the effect of grass hay versus grain (maize = corn) on the properties of the milk to promote cardiovascular disease.

“14 Holstein dairy cows were fed…either grass hay (GH) or maize silage (MS). Milk samples were collected…and fatty acid (FA) profiles were analyzed…Milk from animals fed the GH-diet contained lower concentrations of saturated FAs and higher levels of polyunsaturated FAs (PUFAs). Feeding additional hay also increased conjugated linoleic acid and n-3 FA levels and decreased C16:0 levels.”

What do these differences in fatty acids mean for cardiovascular disease risk?

“Increases in both PUFAs and n-3 FAs resulted in lower atherogenic and thrombogenic indices in milk from animals fed the GH diet compared with those fed the MS diet. A complete substitution of GH for MS appeared to improve milk FA profiles….”

Too bad the authors of the Australian study weren’t able to specify what those Australian cows ate. But another fascinating study just published in the American Journal of Clinical Nutrition sheds more light on the matter. The authors begin by observing:

“Despite the high saturated fat content of dairy products, no clear association between dairy product intake and risk of myocardial infarction (MI) has been observed. Dairy products are the main source of conjugated linoleic acid (CLA; 18:2n–7t), which is produced by the ruminal biohydrogenation of grasses eaten by cows. Pasture-grazing dairy cows have more CLA in their milk than do grain-fed cows. Some animal models have reported beneficial effects of CLA on atherosclerosis.”

The authors wanted to determine the association between CLA in adipose tissue and risk of MI [myocardial infarction]. They used 1813 individuals with non-fatal heart attacks compared to matched controls, in Costa Rica where people use traditional pasture-grazing for dairy cows. What did their data show?

“Adipose tissue CLA was associated with a lower risk of MI…Dairy intake was not associated with risk of MI, despite a strong risk associated with saturated fat intake.”

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Yet another study on the benefits of coffee was just published in the Journal of Agricultural and Food Chemistry. This ones demonstrates how this salubrious beverage improves insulin function and fatty liver by reducing inflammation. The authors observe:

“Epidemiological surveys have demonstrated that habitual coffee consumption reduces the risk of type 2 diabetes. The aim of this work was to study the antidiabetic effect of coffee and caffeine in spontaneously diabetic KK-Ay mice.”

The mice were not taken to Starbucks for mini espresso shots, but were…

“…given regular drinking water (controls) or 2-fold diluted coffee for 5 weeks.”

The results were pretty amazing:

“Coffee ingestion ameliorated the development of hyperglycemia and improved insulin sensitivity. White adipose tissue mRNA levels of inflammatory cytokines (MCP-1, IL-6, and TNFα), adipose tissue MCP-1 concentration, and serum IL-6 concentration in the coffee group were lower than the control group. Moreover, coffee ingestion improved the fatty liver.”

The authors summed up their findings by stating:

“…coffee exerts a suppressive effect on hyperglycemia by improving insulin sensitivity, partly due to reducing inflammatory cytokine expression and improving fatty liver. Moreover, caffeine may be one of the effective antidiabetic compounds in coffee.”

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The authors of this study published recently in the journal Human Reproduction analyzed 12 years of data from the Nurses’ Health Study II to discriminate any link between dietary fat intake and the risk of endometriosis. Their analysis revealed that…

“Although total fat consumption was not associated with endometriosis risk, those women in the highest fifth of long-chain omega-3 fatty acid consumption were 22% less likely to be diagnosed with endometriosis…In addition, those in the highest quintile of trans-unsaturated fat intake were 48% more likely to be diagnosed with endometriosis.”

Considering the other well-known deleterious effects of trans fats, their conclusion is easy to digest:

“These data suggest that specific types of dietary fat are associated with the incidence of laparoscopically confirmed endometriosis, and that these relations may indicate modifiable risk. This evidence additionally provides another disease association that supports efforts to remove trans fat from hydrogenated oils from the food supply.”

By the way, endometriosis is not always so easy to diagnose. Another paper published in the same journal documents the accuracy of a non-invasive diagnosis of endometriosis using plasma (blood) biomarkers:

“Plasma levels of IL-6, IL-8 and CA-125 were increased in all women with endometriosis and in those with minimal–mild endometriosis, compared with controls. In women with moderate–severe endometriosis, plasma levels of IL-6, IL-8 and CA-125, but also of hsCRP, were significantly higher than in controls.”

Yet again we see the diagnostic importance of cytokines (IL-6 and IL-8 in this case). The authors affirm that this method has good sensitivity and specificity:

“Using stepwise logistic regression, moderate–severe endometriosis was diagnosed with a sensitivity of 100% (specificity 84%) and minimal–mild endometriosis was detected with a sensitivity of 87% (specificity 71%) during the secretory phase.”

Action points: (1) Minimize trans fats in your diet in any case. (2) If you suspect an inflammatory disorder ask your doctor about tests for cytokines.

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