Meal Fatty Acid Uptake in Visceral Fat in Women
Objective: Differential meal fat uptake into adipose tissue depots may be a determinant of body fat distribution.
Research Design and Methods: We used the meal fat tracer/adipose tissue biopsy approach to compare the effects of meal fat content on the fat uptake into visceral and upper and lower body subcutaneous fat depots in 21 premenopausal women. [H]triolein was used to trace the fate of fatty acids from a normal-fat or high-fat meal.
Results: The proportion of dietary fat uptake into the three depots did not differ between meals; visceral fat accounted for only ∼5% of meal fat disposal irrespective of visceral fat mass. For the women consuming the normal-fat meal, the uptake of meal fatty acid into femoral fat (milligrams meal fat per gram lipid) increased as a function of leg fat mass (r = 0.68, P < 0.05), which we interpret as increased efficiency of uptake. The opposite pattern was seen in omental fat with the normal-fat meal and in all depots after the high-fat meal. For both meals, ∼40% of meal fat was oxidized (H2O production) after 24 h.
Conclusions: We conclude that greater thigh adipose tissue in women is associated with greater efficiency of meal fat storage under conditions of energy balance, whereas the opposite is seen with visceral fat. These findings imply that different mechanisms may regulate fatty acid uptake in different depots, which may in turn impact on body fat distribution.
Because of the health implications of upper body/visceral obesity we and others are interested in the contribution of competing regional fat storage processes in determining body fat distribution. This is of special interest given the possible role of visceral adipose tissue lipolysis in the metabolic complications of obesity. Under weight stable conditions, fatty acid uptake into an adipose tissue depot should equal lipolysis from this depot. Therefore, the direct measurement of regional meal fat uptake provides an indirect measure of regional lipolysis and clues as to how variations in regional fat gain develop.
We found greater efficiency of uptake (milligrams meal fat per gram lipid) in the upper body subcutaneous (UBSQ) fat than lower body subcutaneous (LBSQ) fat in both lean men and women under isoenergetic conditions. In addition, we reported that a high-fat/calorie meal increased the "efficiency" of LBSQ meal fatty acid uptake in women compared with men. Although the previous study provides clues to sex-specific regional fat distribution, it does not address how obese individuals may respond to a similar high-fat challenge nor does it address the role of visceral fat.
MÃ¥rin et al. first used the meal fatty acid tracer/adipose biopsy approach to study visceral adipose tissue metabolism in men after a high-fat meal. They found greater meal fat uptake into visceral than into subcutaneous abdominal fat but were not able to assess LBSQ fat, to compare their findings to a normal-fat meal, or to measure meal fat oxidation. We suggest that by combining all of these measures, it is possible to better understand the contribution of dietary fat uptake in determining regional fat mass.
The purpose of this study was to assess the effect of meal fat content on the disposal of dietary fat in women with a wide range of body fat distribution. We measured meal fatty acid oxidation and uptake into subcutaneous and visceral adipose tissue. The null hypothesis was that the efficiency of meal fat uptake (in milligrams meal fat per gram lipid) would be similar between regional fat depots and between individuals with different amounts of body fat.
Objective: Differential meal fat uptake into adipose tissue depots may be a determinant of body fat distribution.
Research Design and Methods: We used the meal fat tracer/adipose tissue biopsy approach to compare the effects of meal fat content on the fat uptake into visceral and upper and lower body subcutaneous fat depots in 21 premenopausal women. [H]triolein was used to trace the fate of fatty acids from a normal-fat or high-fat meal.
Results: The proportion of dietary fat uptake into the three depots did not differ between meals; visceral fat accounted for only ∼5% of meal fat disposal irrespective of visceral fat mass. For the women consuming the normal-fat meal, the uptake of meal fatty acid into femoral fat (milligrams meal fat per gram lipid) increased as a function of leg fat mass (r = 0.68, P < 0.05), which we interpret as increased efficiency of uptake. The opposite pattern was seen in omental fat with the normal-fat meal and in all depots after the high-fat meal. For both meals, ∼40% of meal fat was oxidized (H2O production) after 24 h.
Conclusions: We conclude that greater thigh adipose tissue in women is associated with greater efficiency of meal fat storage under conditions of energy balance, whereas the opposite is seen with visceral fat. These findings imply that different mechanisms may regulate fatty acid uptake in different depots, which may in turn impact on body fat distribution.
Because of the health implications of upper body/visceral obesity we and others are interested in the contribution of competing regional fat storage processes in determining body fat distribution. This is of special interest given the possible role of visceral adipose tissue lipolysis in the metabolic complications of obesity. Under weight stable conditions, fatty acid uptake into an adipose tissue depot should equal lipolysis from this depot. Therefore, the direct measurement of regional meal fat uptake provides an indirect measure of regional lipolysis and clues as to how variations in regional fat gain develop.
We found greater efficiency of uptake (milligrams meal fat per gram lipid) in the upper body subcutaneous (UBSQ) fat than lower body subcutaneous (LBSQ) fat in both lean men and women under isoenergetic conditions. In addition, we reported that a high-fat/calorie meal increased the "efficiency" of LBSQ meal fatty acid uptake in women compared with men. Although the previous study provides clues to sex-specific regional fat distribution, it does not address how obese individuals may respond to a similar high-fat challenge nor does it address the role of visceral fat.
MÃ¥rin et al. first used the meal fatty acid tracer/adipose biopsy approach to study visceral adipose tissue metabolism in men after a high-fat meal. They found greater meal fat uptake into visceral than into subcutaneous abdominal fat but were not able to assess LBSQ fat, to compare their findings to a normal-fat meal, or to measure meal fat oxidation. We suggest that by combining all of these measures, it is possible to better understand the contribution of dietary fat uptake in determining regional fat mass.
The purpose of this study was to assess the effect of meal fat content on the disposal of dietary fat in women with a wide range of body fat distribution. We measured meal fatty acid oxidation and uptake into subcutaneous and visceral adipose tissue. The null hypothesis was that the efficiency of meal fat uptake (in milligrams meal fat per gram lipid) would be similar between regional fat depots and between individuals with different amounts of body fat.
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