健康生活學

剛吃飽又「口痕」想吃東西?9招對抗「假性飢餓」騙局

2023/01/31

剛剛吃飽又覺得肚餓?經常「口痕」想吃零食?在寒冷的天氣下更令人不自覺地越吃越多。肚餓時當然應該進食,避免餓壞自己,但其實這些飢餓感有可能只是幻象。以下教你9招對抗假性飢餓,別再被假的飢餓感蒙蔽而導致增磅。

什麼是假性飢餓?

首先,我們要明白為什麼人會感到肚餓。由於人體的大腦是以血糖作為運作的燃料來源,如果血糖過低,大腦便會發出「飢餓指令」,命令身體趕快進食,從而恢復血糖水平以維護大腦的正常運作。透過進食令血糖水平上升,而胰臟在進食後會分泌適量的胰島素來平衡上升的血糖水平。1-3

進食過量會令血糖飆升,胰臟就必須分泌大量胰島素來達致降血糖功能,有機會因為血糖快速下降而產生飢餓感。血糖忽高忽低會令血糖調節能力出現問題,產生「假性飢餓」。加上胰島素是用來儲存能量的荷爾蒙,胰島素過高,會驅使身體進食高糖、高脂、高熱量的食物來補充能量。1-4

什麼因素會誘發假性飢餓?1

  • 經常處於持續疲勞的狀態
  • 睡醒仍感到疲倦,睡超過8小時仍覺得不足夠
  • 經常想吃甜食或喝含糖飲料
  • 工作時想吃東西提神
  • 喝咖啡、茶等提神飲品後,仍提不起勁
  • 壓力越大的人,會攝取越多咖啡因及糖
  • 飲食不定時、邊吃邊工作、吃得過快、經常大吃大喝或餓肚子
  • 女性在生理期,食慾會增加

為什麼冬天更容易肚餓?

  • 調節體溫:寒冷的天氣下,身體需要更多能量製造熱能以維持體溫5
  • 日照時間短:血清素減少導致對碳水化合物、甜食的渴望增加6,7
  • 荷爾蒙水平變化:負責抑制食慾的瘦素(Leptin)減少,導致食慾增加8

什麼是高胰島素血症(Hyperinsulinemia)?

高胰島素血症是指血中胰島素相對葡萄糖的濃度過高。現今的飲食習慣偏向高糖、高脂、高熱量,加上運動減少,導致能量過剩。常吃白飯、麵包等令大部分人的胰島素值偏高,代謝失調。高胰島素血症令人時常感到飢餓、想吃甜食,繼而增加肥胖、糖尿病、代謝綜合症、多囊性卵巢綜合症等風險。1,9

為何突然想吃某種食物?

這反映身體缺乏某種營養素,提醒我們需要補充:

  • 巧克力
    • 缺乏:鎂(有助肌肉及骨骼成長,穩定血壓及血糖)10,11
    • 較健康的代替品:堅果、牛油果12
  • 鹹食
    • 缺乏:鈉(保持體液平衡、穩定血壓、維持肌肉和神經系統操作)13,14
    • 較健康的代替品:水(脫水的狀態增加我們對鹽分的渴望)15
  • 肉類
    • 缺乏:鐵(負責製造紅血球)16
    • 較健康的代替品:魚、菠菜、豆類17

如何克服「假性飢餓」?

要避免因假性飢餓而過量進食,必須從食物的種類、份量、時間方面調整,幫助身體恢復血糖調節能力,才能有效控制體重:1,18-21

  1. 減少碳水化合物的攝取量

碳水化合物食物的攝取,至少要減少到目前的2/3,最多減至1/2。碳水化合物食物包括白飯、麵包、餅乾、 薯條、粟米片、冬甩

  1. 進食碳水化合物時同時進食脂肪和蛋白質

同時進食脂肪和蛋白質如肉類、家禽、魚類、蛋類及乾豆類可減輕碳水化合物對血糖的影響,並降低進食時的升糖負荷

  1. 少食多餐

早、午、晚餐三餐一定要吃,但不要吃到飽,少食多餐

  1. 慢吃

慢慢咀嚼食物能將「吃飽」的訊息傳遞到大腦,而抑制食慾的激素開始起作用,進而提升飽足感,令食量減少

  1. 吃飽後不要立即吃甜食

餐後吃高升糖負荷的水果、含糖飲料、茶、咖啡因飲料、蛋糕等,會導致血糖調節能力出現問題

  1. 餐與餐之間可以吃一點低升糖負荷的零食

果仁、乳酪等低升糖負荷的零食有助持續、穩定地為身體提供能量,降低食慾

  1. 嚼香口膠

感到肚餓時嚼香口膠有助減低食慾,增加飽腹感

  1. 喝水

肚餓時喝水可以增加飽肚感,從而減低食量

  1. 進食時關掉螢幕

電子螢幕釋放的藍光會增加飢餓感,特別是進食前及進食時

參考資料:

  1. 綠食譜研究所. 低GL瘦肚沙拉:專為亞洲人設計!世界營養權威推崇的112飲食法,教你減醣、甩油,打造不復胖的瘦體質!. Available at: https://www.books.com.tw/web/sys_serialtext/?item=0010787552&page=2. Accessed 12 January 2023
  2. Ludwig. The glycemic index: physiological mechanisms relating to obesity, diabetes, and cardiovascular disease. Jama. 2002.
  3. Lepkovsky et al. Some basic mechanisms of hunger and satiety. Proceedings of the Nutrition Society. 1962.
  4. Harris. Hyperinsulinism, a Definite Disease Entity: Etiology, Pathology, Symptoms, Diagnosis, Prognosis and Treatment of Spontaneous Insulogenic Hypoglycemia (Hyperinsulinism). Journal of the American Medical Association. 1933.
  5. Marriot. Effects of Heat on Appetite. Nutritional Needs in Hot Environments: Applications for Military Personnel in Field Operations. 1993.
  6. NHS inform. Do you have the winter blues? Available at: https://www.nhsinform.scot/healthy-living/mental-wellbeing/low-mood-and-depression/do-you-have-the-winter-blues. Accessed 12 January 2023
  7. Franklin. Brighten Up Your Winter. Your Best Health Under the Sun. 2007.
  8. Friedman. Leptin and the regulation of body weigh. The Keio journal of medicine. 2011.
  9. Cleveland Clinic. Hyperinsulinemia. Available at: https://my.clevelandclinic.org/health/diseases/24178-hyperinsulinemia. Accessed 20 January 2023
  10. Bruinsma et al. Chocolate: food or drug? Journal of the American Dietetic Association. 1999.
  11. Healthdirect. Magnesium and your health. Available at: https://www.healthdirect.gov.au/magnesium. Accessed 12 January 2023
  12. Healthdirect. Foods high in magnesium. Available at: https://www.healthdirect.gov.au/foods-high-in-magnesium. Accessed 12 January 2023
  13. 衞生署家庭健康服務. 礦物質. Available at: https://www.studenthealth.gov.hk/tc_chi/health/health_dn/health_dn_rb.html. Accessed 12 January 2023
  14. Hurley et al. The biopsychology of salt hunger and sodium deficiency. Pflügers Archiv-European Journal of Physiology. 2015.
  15. De Luca et al. Water deprivation and the double-depletion hypothesis: common neural mechanisms underlie thirst and salt appetite. Brazilian journal of medical and biological research. 2007.
  16. National Health Service. Iron. Available at: https://www.nhs.uk/conditions/vitamins-and-minerals/iron/. Accessed 12 January 2023
  17. Healthdirect. Foods high in iron. Available at: https://www.healthdirect.gov.au/foods-high-in-iron. Accessed 12 January 2023
  18. Hawton wt al. Slow down: behavioural and physiological effects of reducing eating rate. Nutrients. 2018.
  19. Healthline. A Beginner’s Guide to the Low Glycemic Diet. Available at: https://www.healthline.com/nutrition/low-glycemic-diet#the-glycemic-index-gi. Accessed 12 January 2023
  20. Hetherington. Effects of chewing gum on short-term appetite regulation in moderately restrained eaters. Appetite. 2011.
  21. 食物安全中心. 營養素與健康:能量及蛋白質. Available at: https://www.cfs.gov.hk/tc_chi/multimedia/multimedia_pub/multimedia_pub_fsf_29_02.html. Accessed 20 January 2023
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