The highest level of evidence from systematic review s and meta-analyses of controlled trials has not shown that fructose-containing sugars behave any differently from other forms of digestible carbohydrates .
Fructose-containing sugars can only lead to weight gain and other unintended harms on cardiometabolic risk factors insofar as the excess calories they provide .
Prospect i ve cohort studies , which provide the strongest observational evidence , have shown an association between fructose-containing sugars and cardiometabolic risk including weight gain , cardiovascular disease outcomes and diabetes only when restricted to sugar-sweetened beverages and not for sugars from other sources .
In fact , sugar-sweetened beverages are a marker of an unhealthy lifestyle and their drinkers consume more calories , exercise less , smoke more and have a poor dietary pattern .
Fructose-containing sugars are a focus of attention as a public health target for their putative role in obesity and cardiometabolic disease including diabetes .
The fructose moiety is singled out to be the primary driver for the harms of sugars due to its unique endocrine signal and pathophysiological role .
However , this is only supported by ecological studies , animal models of overfeeding and select human intervention studies with supraphysiological doses or lack of control for energy .
Dietary Patterns and Risk for Type 2 Diabetes Mellitus in U.S. Men
The prevalence of type 2 diabetes mellitus is rapidly increasing in the United States ( 1 , 2 ) and worldwide ( 3 ) . Ecologic studies ( 4 ) , migration studies ( 4 , 5 ) , and analyses of secular trends ( 4 , 6 ) suggest that adoption of a western diet may be associated with increased incidence of type 2 diabetes . However , these studies could not separate the effects of diet from those of other risk factors , such as obesity and physical activity . Studies of the relation between diet and incidence of type 2 diabetes on an individual level have predominantly focused on intake of macronutrients and fiber ( 7 ) . However , these dietary factors alone probably explain only part of the effect of diet on glucose metabolism . Other nutrients , additives , contaminants , and unknown compounds and the physical properties of foods and interactions between nutrients ( for example , with respect to bioavailability ) may play a role in the deterioration of glucose metabolism . Hence , the examination of effects of food consumption may be an important complementary approach . Recently , the analysis of patterns of food consumption by using factor analysis has emerged as a useful tool for elucidating relationships between diet and health ( 8 - 11 ) . The overall dietary pattern may affect health more than individual foods and nutrients do . Furthermore , dietary patterns reflect the way foods are consumed in reality , which may provide insight into possibilities for dietary changes and may facilitate the translation of findings to public health recommendations . Recent dietary intervention studies have indicated that interventions focused on dietary patterns can decrease blood pressure ( 12 ) and reduce cardiovascular complications ( 13 ) . Data on dietary patterns and risk for type 2 diabetes are sparse . Although two cross-sectional studies of dietary patterns and diabetes have been conducted ( 11 , 14 ) , these studies incompletely controlled for confounding by other lifestyle factors . Therefore , we prospect ively examined the association between major dietary patterns and risk for type 2 diabetes in a large prospect i ve study of U.S. professional men with extensive , repeatedly obtained information on diet and other lifestyle factors . Methods Participants The Health Professionals Follow-up Study started in 1986 , when 51 529 male health professionals ( dentists , veterinarians , pharmacists , optometrists , osteopathic physicians , and podiatrists ) completed a detailed mailed question naire on medical history , diet , and other potential risk factors for major diseases .  The participants lived in all 50 U.S. states , were predominantly white , and were 40 to 75 years of age in 1986 . We excluded from the current analysis 1595 men who did not satisfy the a priori criteria of reporting daily energy intake of 3.3 to 17.6 MJ ( 800 to 4200 kcal/24 h ) and leaving fewer than 70 responses blank of the 131 food items on the diet question naire ( < 5 % had > 11 blanks ) . We also excluded men who reported having diabetes , cardiovascular disease ( myocardial infa rct ion , angina pectoris , coronary artery surgery , or stroke ) , or cancer ( except nonmelanoma skin cancer ) at baseline because having these diagnoses may affect diet or reporting of diet . After exclusions , the study sample comprised 42 504 men , who were followed for incidence of type 2 diabetes and other diseases for 12 years ( 1986 to 1998 ) . Every 2 years , the participants received question naires by mail that asked for up date d information on exposures and newly diagnosed diseases . The follow-up rate for potential person-years was about 97 % for nonfatal events . We identified deaths by reports from family members , coworkers , or postal authorities or through systematic search es of the National Death Index . Assessment of Dietary Patterns To assess dietary intake , we used a 131-item semiquantitative food-frequency question naire in 1986 , 1990 , and 1994 . The question naire specified for each food a commonly used unit or portion size , and the participants were asked to indicate how often , on average , they had consumed a given amount of the specified food during the past year . Each such item provided nine possible responses , ranging from never or less than once a month to 6 or more times per day . To reduce within-respondent variation and to best represent long-term dietary habits , we averaged the dietary intakes from all available dietary question naires up to the start of each follow-up interval ( the average of the 1986 and 1990 dietary intakes was related to incidence of type 2 diabetes between 1990 and 1994 ) ( 15 ) . To identify dietary patterns , we applied factor analysis to data from the food-frequency question naire . First , we grouped the food items on the question naire into 37 predefined food groups . We combined food items that were similar in nutrient profile and culinary use ( for example , spinach , iceberg or head lettuce , and romaine or leaf lettuce were combined into green leafy vegetables ) . We classified a food item individually if its composition differed substantially from that of other foods ( for example , eggs or pizza ) or if we suspected that it represents a particular dietary habit ( for example , wine or French fries ) . Second , we applied the principal components program for factor analysis of SAS software ( 16 ) with varimax rotation to the 37 food groups . Factor analysis aggregates correlated variables . The obtained factors are linear combinations of the included variables , explaining as much of the variation in the original variables as possible . Our analysis retained two factors based on the eigenvalue of the factors , the Scree test , and the interpretability of the derived factors , and we labeled these diets as the prudent pattern and the western pattern ( 9 ) . Third , for each participant , we calculated a  prudent pattern score and a  western pattern score  by summing the st and ardized intake of foods , weighted by the factor loadings of the foods ( 17 ) . We used these scores to rank participants according to the degree to which they conformed to each dietary pattern . We divided dietary pattern scores into quintiles ; thus , on this basis of his scores , each participant was grouped in a prudent-pattern quintile and a western-pattern quintile . To test the validity and reproducibility of the assessment of the dietary pattern scores by the food-frequency question naire , we examined a subgroup of 127 participants ( 9 ) . The Pearson correlation coefficient ( corrected for week-to-week variation in the diet records ) for a comparison between the responses to the food-frequency question naire and the diet records was 0.52 for the prudent dietary pattern and 0.74 for the western dietary pattern . Assessment of Nondietary Exposures The 1986 question naire and each biennial follow-up question naire assessed weight , smoking status , and physical activity .  Participants provided information on age , diagnosis of hypertension and hypercholesterolemia , and height in 1986 and on family history of diabetes in 1987 . The criterion for family history of type 2 diabetes was having at least one first-degree relative with a diagnosis of diabetes after 30 years of age . For each participant , we determined a physical activity level , measured in weekly metabolic equivalent hours , on the basis of reported time spent on various activities , which we weighted according to intensity level ( 18 ) . The validity of self-reported weight ( 19 ) and physical activity ( 18 ) in this cohort has been reported previously . Ascertainment of Type 2 Diabetes Mellitus We mailed a supplementary question naire on symptoms , diagnostic tests , and medication use to participants who indicated on any biennial follow-up question naire that he had received a diagnosis of diabetes mellitus . Confirmation of diabetes required at least one of the following : 1 ) an elevated plasma glucose level ( fasting plasma glucose level 7.8 mmol/L [ 140 mg/dL ] ; r and om plasma glucose level 11.1 mmol/L [ 200 mg/dL ] ; or  plasma glucose level after 2 hours or more during an oral glucose tolerance test 11.1 mmol/L [ 200 mg/dL ] ) plus at least one classic symptom [ excessive thirst , polyuria , weight loss , or hunger ] ; 2 ) at least two elevated plasma glucose levels measured on different occasions ; or 3 ) treatment with insulin or oral hypoglycemic medication . We excluded men who reported having type 1 diabetes on the supplementary question naire . These criteria for diabetes are consistent with those from the World Health Organization in 1985 ( 20 ) . We did not use the current diabetes classification of the American Diabetes Association ( 21 ) because among the men in our study , most cases of diabetes were diagnosed before these criteria were published . The validity of our assessment of type 2 diabetes was verified with medical records in a sub sample of 71 participants . A physician blinded to the information on the supplementary question naire review ed the records according to the diagnostic criteria . Of the 71 participants classified as having type 2 diabetes , 12 had incomplete medical recordsfor example , absent laboratory data ( n = 2 ) or only one set of laboratory data ( n = 9 ) . We confirmed the classification of type 2 diabetes in 57 ( 97 % ) of the other 59 other men in the sub sample . One participant denied having diabetes , and another participant lacked evidence of diabetes in his su bmi tted records . Statistical Analysis We used pooled logistic regression analyses with 2-year intervals to estimate the adjusted relative risk for each quintile compared with the lowest quintile of intake . With short time intervals and low rates of events , this approach gives results very similar to those of Cox proportional-hazards analyses ( 22 ) . Participants who died or received a diagnosis of diabetes during a 2-year cycle were censored at the end of that 2-year period and were not entered in any subsequent 2-year cycle . We used the cumulative average of available dietary assessment s up to the start of each 2-year follow-up interval ( 15 ) . We stopped updating a participant 's dietary
The highest level of evidence from systematic review s and meta-analyses of controlled trials has not shown that fructose-containing sugars behave any differently from other forms of digestible carbohydrates .
Fructose-containing sugars can only lead to weight gain and other unintended harms on cardiometabolic risk factors insofar as the excess calories they provide .
Prospect i ve cohort studies , which provide the strongest observational evidence , have shown an association between fructose-containing sugars and cardiometabolic risk including weight gain , cardiovascular disease outcomes and diabetes only when restricted to sugar-sweetened beverages and not for sugars from other sources .
In fact , sugar-sweetened beverages are a marker of an unhealthy lifestyle and their drinkers consume more calories , exercise less , smoke more and have a poor dietary pattern .
Fructose-containing sugars are a focus of attention as a public health target for their putative role in obesity and cardiometabolic disease including diabetes .
The fructose moiety is singled out to be the primary driver for the harms of sugars due to its unique endocrine signal and pathophysiological role .
However , this is only supported by ecological studies , animal models of overfeeding and select human intervention studies with supraphysiological doses or lack of control for energy .