In the last 6 months, the New York Times has posted several articles citing
studies on dietary fat intake.
Not exact matches
(See:
Study: Saturated
Fat Not Associated with Risk of Coronary Artery Disease, Coconut Oil and Dairy
Fat Healthy and Big Pharma
Study: USDA
Dietary Guidelines
on Fats are Wrong.)
This
study confirms what many other
studies also show, that the USDA
dietary guidelines» advice
on fats and oils has been completely wrong for many years now.
The
study's focus
on added sugars detracts from the issue of overweight and obesity from the real
dietary issue — lowering energy (kilojoule) intake from any energy source —
fat, protein, starch or sugars» said the Council's CEO, Mr Geoff Parker.
Studies on dietary choices leading to obesity have focused overwhelmingly
on the sugar and
fat content of snacks, fast foods, beverages, and confectionery (67, 68).
One of the biggest
studies done recently
on nutrition, from the Women's Health Initiative
Dietary Modification Trial, showed no real benefits from a low -
fat diet.
Specifically, Ebbeling's group
studied three
dietary paradigms: an Atkins» low - carb diet (60 percent of calories from
fat, 10 percent from carbs); a mixed diet with foods generally low
on the glycemic index (40 percent of calories from
fat, 40 percent from carbs); and a low -
fat diet with a mix of carbohydrates generally high
on the glycemic index (20 percent of calories from
fat, 60 percent from carbs).
The
study is the most detailed and powerful examination to date
on how
dietary fats impact health.
The
study that Ian Johnson cites in his comment piece
on dietary fats reported an association between the intake of...
Which is not to say that this lost
study will change views
on dietary fat and heart health.
The
study, published in PLOS ONE, is the first to consider the differing effects of
dietary fats on prediabetes as two separate conditions, although previous
studies have shown that
dietary fats have an effect
on insulin sensitivity.
When a paper published
on 17 March questioned whether
fats from fish or vegetable oils are healthier than those in meat or butter, it quickly made headlines around the world; after all, the
study seemed to debunk a cornerstone of many
dietary guidelines.
The
study that Ian Johnson cites in his comment piece
on dietary fats reported an association between the intake of saturated
fat and heart disease and cancer (16 July, p 18).
A
study published in The American Journal of Medicine reveals that a whole diet approach, which focuses
on increased intake of fruits, vegetables, nuts, and fish, has more evidence for reducing cardiovascular risk than strategies that focus exclusively
on reduced
dietary fat.
«In this
study, researchers evaluated the effect of
dietary fats on one particular chromatin gene known to lengthen roundworm lifespan.
Studies have shown that as long as
dietary protein and
fat are sufficient, a diet that is higher in carbs results in approximately the same amount of
fat loss as one very low in carbs (any difference in weight loss was due to extra water weight loss
on the low carb diet) 3.
Colon cancer occurs when high levels of
dietary vegetable oils and hydrogenated
fats, along with certain carcinogens, are acted
on by certain enzymes in the cells lining the colon, leading to tumor formation.14 This explains the fact that in industrialized countries, where there are many carcinogens in the diet and where consumption of vegetable oils and carcinogens is high, some
studies have correlated meat - eating with colon cancer; but in traditional societies, where vegetable oils are absent and the food is free of additives, meat - eating is not associated with cancer.
27
Studies cited by the 2010 DGAC Report demonstrate varied metabolic responses to lowered
dietary saturated
fat, with certain subpopulations exhibiting adverse rather than improved health outcomes.3 Two recent comprehensive meta - analyses indicate that saturated
fat is not linked to heart disease.28, 29 In fact, in a definitive review of forty - eight clinical trials, with over sixty - five thousand participants, the reduction or modification of
dietary fat had no effect
on mortality, cardiovascular mortality, heart attacks, stroke, cancer, or diabetes.30 Yet, avoiding saturated
fat remains a cornerstone of national
dietary guidance.
There's a lot of anecdotal evidence that this eating strategy works for some people, but according to a number of scientific
studies, the frequency of meals has absolutely no effect
on fat loss [1, 2], but does have beneficial metabolic effects
on dietary thermogenesis and insulin sensitivity [3](in other words, it helps regulate your blood sugar levels, which in turn can help keep your appetite under control).
Along the lines of your lecture, do you have any thoughts about that (small but intriguing)
study that raises the possibility that «
dietary protein source may modify the effects of saturated
fat on atherogenic lipoproteins»; ie, eating butter with your beef may not be a cool thing to do?
Some important
studies include: • Beneficial effects of a high carbohydrate, high fiber diet
on hyperglycemic diabetic men (1976) • Response of non-insulin-dependent diabetic patients to an intensive program of diet and exercise (1982) • Diet and exercise in the treatment of NIDDM: The need for early emphasis (1994) • Toward improved management of NIDDM: A randomized, controlled, pilot intervention using a low
fat, vegetarian diet (1999) • The effects of a low -
fat, plant - based
dietary intervention
on body weight, metabolism, and insulin sensitivity (2005) • A low -
fat vegan diet improves glycemic control and cardiovascular risk factors in a randomized clinical trial in individuals with type 2 diabetes (2006) • A low -
fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74 - wk clinical trial (2009) • Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes (2011) • Glycemic and cardiovascular parameters improved in type 2 diabetes with the high nutrient density (HND) diet (2012)
She has headed a number of
studies on the content and effects of trans fatty acids in America and Israel and has successfully challenged government assertions that
dietary animal
fat causes cancer and heart disease.
«'' Although
dietary recommendations have focused
on restricting saturated
fat (SF) consumption to reduce cardiovascular disease (CVD) risk, evidence from prospective
studies has not supported a strong link between total SF intake and CVD events... A higher intake of dairy SF was associated with LOWER CVD risk.
Ancel Keys» work
on the «Seven Countries»
study was references, which looked at the correlation between
dietary fat and blood cholesterol levels.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3396447/ — «Although
dietary recommendations have focused
on restricting saturated
fat (SF) consumption to reduce cardiovascular disease (CVD) risk, evidence from prospective
studies has not supported a strong link between total SF intake and CVD events... A higher intake of dairy SF was associated with LOWER CVD risk.
The
study investigated the effect of
dietary fat (classified as total, saturated, monounsaturated, polyunsaturated, omega 6, omega 3 and trans)
on a range of preclinical and clinical outcomes in women having IVF.
As this paper from 2009 explains, the supposed link between
dietary and serum cholesterol stems from
studies that had fundamental design flaws, failed to separate the effects of cholesterol different types of
fat intake, or were performed
on animals that are obligate herbivores (hey there, rabbits!).
Dietary fat intake has been previously
studied for its effect
on reproductive health; for example, a high intake of trans -
fats has been associated with ovulatory infertility (as in polycystic ovary syndrome) and miscarriage, while saturated
fats have been related to lower sperm concentrations.
On a positive note, in line with our ancestors»
dietary habits, recent
studies have shown that natural saturated
fat sources are not only delicious, but also essential to our health.
Beginning in 1978, a series of
studies were published in the Journal of the National Cancer Institute that looked at the effects of
dietary fat on tumor growth.
«The positive ecological correlations between national intakes of total
fat and saturated fatty acids and cardiovascular mortality found in earlier
studies were absent or negative in the larger, more recent
studies,» the authors wrote, concluding that «the harmful effect of
dietary saturated fatty acids and the protective effect of
dietary polyunsaturated fatty acids
on atherosclerosis and cardiovascular disease are questioned.»
The
study, entitled «Food4Me ``, investigated 1,500 participants in seven European countries who were randomly given personalized
dietary advice based
on their genetic data, or instead told to follow standard
dietary prescriptions such as eating lots of fruits and vegetables (don't you just love how those two are always «lumped together»), lean meats (I run like the plague when I see a lean meat because I've never once been dressing an animal I've hunted and found meat void of
fat) and whole grains (which can spike your blood sugar higher than a Snicker's Bar).
A possible reason for the alleviation of the athlete's symptoms in this case
study (gastrointestinal distress, fatigue, hunger, and menstrual complaints) in response to the implementation of the exercise and
dietary recommendations may relate to the removal of physiological stress
on the HPA axis, stemming largely via the improved whole body
fat oxidation rates.
In a high quality seven day, randomized, crossover
study conducted by Sunehag et al. (2002), twelve healthy, non-obese adolescents (six males, six females) were maintained at home
on prepared, isocaloric diets containing 60 % carbohydrate, 25 %
fat, and 15 % protein, with 10 % or 40 % of the carbohydrate (6 or 24 % of
dietary energy) content provided by fructose (low fructose or high fructose diet, respectively)... The total amounts of fructose ingested in the low and high fructose diets were estimated to be 36 and 133 g / day in females and 40 and 136 g / day in males.
Furthermore, in most human intervention
studies, changes in
dietary fat quality had no effects
on insulin sensitivity (106, 115).
The theory that
dietary fat causes obesity and heart disease, based
on a couple of terrible
studies in the 1950s, became unchallenged orthodoxy and is only now fading slowly.
Specifically,
studies have shown that eating 100g + of healthy
dietary fats (like fish, olive oil, and avocados) has a positive impact
on cognition and eating processed foods has the inverse effect.